// SPDX-License-Identifier: GPL-2.0-only
/*
 *  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
 */

#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;
        unsigned long           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] = SNDRV_DEFAULT_ENABLE_PNP;

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");

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

/****************************************************************************
                        Module specific functions
 ****************************************************************************/
/* 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,
                                 unsigned long 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(%lu pages) failed\n", nr_pages);
                return -ENOMEM;
        }

        dprintk(1, "vmalloc is at addr 0x%p, size=%lu\n",
                                buf->vaddr,
                                nr_pages << PAGE_SHIFT);

        memset(buf->vaddr, 0, nr_pages << PAGE_SHIFT);
        buf->nr_pages = nr_pages;

        buf->sglist = vzalloc(array_size(sizeof(*buf->sglist), buf->nr_pages));
        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, DMA_FROM_DEVICE);

        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->nr_pages, DMA_FROM_DEVICE);
        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);
        dma_free_coherent(&chip->pci->dev, 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 const 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_obj(*buf);
        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");
                cx25821_alsa_dma_unmap(chip);
                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 const struct snd_pcm_ops snd_cx25821_pcm_ops = {
        .open = snd_cx25821_pcm_open,
        .close = snd_cx25821_close,
        .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;
        strscpy(pcm->name, name, sizeof(pcm->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 __maybe_unused 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;
        }

        strscpy(card->driver, "cx25821", sizeof(card->driver));

        /* 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 = devm_request_irq(&dev->pci->dev, 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;
        }

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

        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);