Initial import

1 files changed, 833 insertions, 0 deletions

diff --git a/drivers/media/pci/cx25821/cx25821-alsa.c b/drivers/media/pci/cx25821/cx25821-alsa.c
new file mode 100644
index 000000000..24f964bcc
--- /dev/null
+++ b/drivers/media/pci/cx25821/cx25821-alsa.c
@@ -0,0 +1,833 @@
+/*
+ *  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 cx25821_riscmem risc;
+	void			*vaddr;
+	struct scatterlist	*sglist;
+	int                     sglen;
+	int                     nr_pages;
+};
+
+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 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)
+
+static int cx25821_alsa_dma_init(struct cx25821_audio_dev *chip, int nr_pages)
+{
+	struct cx25821_audio_buffer *buf = chip->buf;
+	struct page *pg;
+	int i;
+
+	buf->vaddr = vmalloc_32(nr_pages << PAGE_SHIFT);
+	if (NULL == buf->vaddr) {
+		dprintk(1, "vmalloc_32(%d pages) failed\n", nr_pages);
+		return -ENOMEM;
+	}
+
+	dprintk(1, "vmalloc is at addr 0x%08lx, size=%d\n",
+				(unsigned long)buf->vaddr,
+				nr_pages << PAGE_SHIFT);
+
+	memset(buf->vaddr, 0, nr_pages << PAGE_SHIFT);
+	buf->nr_pages = nr_pages;
+
+	buf->sglist = vzalloc(buf->nr_pages * sizeof(*buf->sglist));
+	if (NULL == buf->sglist)
+		goto vzalloc_err;
+
+	sg_init_table(buf->sglist, buf->nr_pages);
+	for (i = 0; i < buf->nr_pages; i++) {
+		pg = vmalloc_to_page(buf->vaddr + i * PAGE_SIZE);
+		if (NULL == pg)
+			goto vmalloc_to_page_err;
+		sg_set_page(&buf->sglist[i], pg, PAGE_SIZE, 0);
+	}
+	return 0;
+
+vmalloc_to_page_err:
+	vfree(buf->sglist);
+	buf->sglist = NULL;
+vzalloc_err:
+	vfree(buf->vaddr);
+	buf->vaddr = NULL;
+	return -ENOMEM;
+}
+
+static int cx25821_alsa_dma_map(struct cx25821_audio_dev *dev)
+{
+	struct cx25821_audio_buffer *buf = dev->buf;
+
+	buf->sglen = dma_map_sg(&dev->pci->dev, buf->sglist,
+			buf->nr_pages, PCI_DMA_FROMDEVICE);
+
+	if (0 == buf->sglen) {
+		pr_warn("%s: cx25821_alsa_map_sg failed\n", __func__);
+		return -ENOMEM;
+	}
+	return 0;
+}
+
+static int cx25821_alsa_dma_unmap(struct cx25821_audio_dev *dev)
+{
+	struct cx25821_audio_buffer *buf = dev->buf;
+
+	if (!buf->sglen)
+		return 0;
+
+	dma_unmap_sg(&dev->pci->dev, buf->sglist, buf->sglen, PCI_DMA_FROMDEVICE);
+	buf->sglen = 0;
+	return 0;
+}
+
+static int cx25821_alsa_dma_free(struct cx25821_audio_buffer *buf)
+{
+	vfree(buf->sglist);
+	buf->sglist = NULL;
+	vfree(buf->vaddr);
+	buf->vaddr = NULL;
+	return 0;
+}
+
+/*
+ * 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)
+{
+	struct cx25821_riscmem *risc = &chip->buf->risc;
+
+	BUG_ON(!chip->dma_size);
+
+	dprintk(2, "Freeing buffer\n");
+	cx25821_alsa_dma_unmap(chip);
+	cx25821_alsa_dma_free(chip->buf);
+	pci_free_consistent(chip->pci, risc->size, risc->cpu, risc->dma);
+	kfree(chip->buf);
+
+	chip->buf = 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 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;
+	chip->buf = buf;
+
+	ret = cx25821_alsa_dma_init(chip,
+			(PAGE_ALIGN(chip->dma_size) >> PAGE_SHIFT));
+	if (ret < 0)
+		goto error;
+
+	ret = cx25821_alsa_dma_map(chip);
+	if (ret < 0)
+		goto error;
+
+	ret = cx25821_risc_databuffer_audio(chip->pci, &buf->risc, buf->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 */
+
+	substream->runtime->dma_area = chip->buf->vaddr;
+	substream->runtime->dma_bytes = chip->dma_size;
+	substream->runtime->dma_addr = 0;
+
+	return 0;
+
+error:
+	chip->buf = NULL;
+	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 const struct pci_device_id 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_new(&dev->pci->dev, 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;
+	}
+
+	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);