// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *  als300.c - driver for Avance Logic ALS300/ALS300+ soundcards.
 *  Copyright (C) 2005 by Ash Willis <ashwillis@programmer.net>
 *
 *  TODO
 *  4 channel playback for ALS300+
 *  gameport
 *  mpu401
 *  opl3
 *
 *  NOTES
 *  The BLOCK_COUNTER registers for the ALS300(+) return a figure related to
 *  the position in the current period, NOT the whole buffer. It is important
 *  to know which period we are in so we can calculate the correct pointer.
 *  This is why we always use 2 periods. We can then use a flip-flop variable
 *  to keep track of what period we are in.
 */

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

#include <sound/core.h>
#include <sound/control.h>
#include <sound/initval.h>
#include <sound/pcm.h>
#include <sound/pcm_params.h>
#include <sound/ac97_codec.h>
#include <sound/opl3.h>

/* snd_als300_set_irq_flag */
#define IRQ_DISABLE             0
#define IRQ_ENABLE              1

/* I/O port layout */
#define AC97_ACCESS             0x00
#define AC97_READ               0x04
#define AC97_STATUS             0x06
#define   AC97_DATA_AVAIL               (1<<6)
#define   AC97_BUSY                     (1<<7)
#define ALS300_IRQ_STATUS       0x07            /* ALS300 Only */
#define   IRQ_PLAYBACK                  (1<<3)
#define   IRQ_CAPTURE                   (1<<2)
#define GCR_DATA                0x08
#define GCR_INDEX               0x0C
#define ALS300P_DRAM_IRQ_STATUS 0x0D            /* ALS300+ Only */
#define MPU_IRQ_STATUS          0x0E            /* ALS300 Rev. E+, ALS300+ */
#define ALS300P_IRQ_STATUS      0x0F            /* ALS300+ Only */

/* General Control Registers */
#define PLAYBACK_START          0x80
#define PLAYBACK_END            0x81
#define PLAYBACK_CONTROL        0x82
#define   TRANSFER_START                (1<<16)
#define   FIFO_PAUSE                    (1<<17)
#define RECORD_START            0x83
#define RECORD_END              0x84
#define RECORD_CONTROL          0x85
#define DRAM_WRITE_CONTROL      0x8B
#define   WRITE_TRANS_START             (1<<16)
#define   DRAM_MODE_2                   (1<<17)
#define MISC_CONTROL            0x8C
#define   IRQ_SET_BIT                   (1<<15)
#define   VMUTE_NORMAL                  (1<<20)
#define   MMUTE_NORMAL                  (1<<21)
#define MUS_VOC_VOL             0x8E
#define PLAYBACK_BLOCK_COUNTER  0x9A
#define RECORD_BLOCK_COUNTER    0x9B

#define DEBUG_PLAY_REC  0

#if DEBUG_PLAY_REC
#define snd_als300_dbgplay(format, args...) printk(KERN_ERR format, ##args)
#else
#define snd_als300_dbgplay(format, args...)
#endif          

enum {DEVICE_ALS300, DEVICE_ALS300_PLUS};

MODULE_AUTHOR("Ash Willis <ashwillis@programmer.net>");
MODULE_DESCRIPTION("Avance Logic ALS300");
MODULE_LICENSE("GPL");

static int index[SNDRV_CARDS] = SNDRV_DEFAULT_IDX;
static char *id[SNDRV_CARDS] = SNDRV_DEFAULT_STR;
static bool enable[SNDRV_CARDS] = SNDRV_DEFAULT_ENABLE_PNP;

module_param_array(index, int, NULL, 0444);
MODULE_PARM_DESC(index, "Index value for ALS300 sound card.");
module_param_array(id, charp, NULL, 0444);
MODULE_PARM_DESC(id, "ID string for ALS300 sound card.");
module_param_array(enable, bool, NULL, 0444);
MODULE_PARM_DESC(enable, "Enable ALS300 sound card.");

struct snd_als300 {
        unsigned long port;
        spinlock_t reg_lock;
        struct snd_card *card;
        struct pci_dev *pci;

        struct snd_pcm *pcm;
        struct snd_pcm_substream *playback_substream;
        struct snd_pcm_substream *capture_substream;

        struct snd_ac97 *ac97;
        struct snd_opl3 *opl3;

        struct resource *res_port;

        int irq;

        int chip_type; /* ALS300 or ALS300+ */

        char revision;  
};

struct snd_als300_substream_data {
        int period_flipflop;
        int control_register;
        int block_counter_register;
};

static const struct pci_device_id snd_als300_ids[] = {
        { 0x4005, 0x0300, PCI_ANY_ID, PCI_ANY_ID, 0, 0, DEVICE_ALS300 },
        { 0x4005, 0x0308, PCI_ANY_ID, PCI_ANY_ID, 0, 0, DEVICE_ALS300_PLUS },
        { 0, }
};

MODULE_DEVICE_TABLE(pci, snd_als300_ids);

static inline u32 snd_als300_gcr_read(unsigned long port, unsigned short reg)
{
        outb(reg, port+GCR_INDEX);
        return inl(port+GCR_DATA);
}

static inline void snd_als300_gcr_write(unsigned long port,
                                                unsigned short reg, u32 val)
{
        outb(reg, port+GCR_INDEX);
        outl(val, port+GCR_DATA);
}

/* Enable/Disable Interrupts */
static void snd_als300_set_irq_flag(struct snd_als300 *chip, int cmd)
{
        u32 tmp = snd_als300_gcr_read(chip->port, MISC_CONTROL);

        /* boolean XOR check, since old vs. new hardware have
           directly reversed bit setting for ENABLE and DISABLE.
           ALS300+ acts like newer versions of ALS300 */
        if (((chip->revision > 5 || chip->chip_type == DEVICE_ALS300_PLUS) ^
                                                (cmd == IRQ_ENABLE)) == 0)
                tmp |= IRQ_SET_BIT;
        else
                tmp &= ~IRQ_SET_BIT;
        snd_als300_gcr_write(chip->port, MISC_CONTROL, tmp);
}

static void snd_als300_free(struct snd_card *card)
{
        struct snd_als300 *chip = card->private_data;

        snd_als300_set_irq_flag(chip, IRQ_DISABLE);
}

static irqreturn_t snd_als300_interrupt(int irq, void *dev_id)
{
        u8 status;
        struct snd_als300 *chip = dev_id;
        struct snd_als300_substream_data *data;

        status = inb(chip->port+ALS300_IRQ_STATUS);
        if (!status) /* shared IRQ, for different device?? Exit ASAP! */
                return IRQ_NONE;

        /* ACK everything ASAP */
        outb(status, chip->port+ALS300_IRQ_STATUS);
        if (status & IRQ_PLAYBACK) {
                if (chip->pcm && chip->playback_substream) {
                        data = chip->playback_substream->runtime->private_data;
                        data->period_flipflop ^= 1;
                        snd_pcm_period_elapsed(chip->playback_substream);
                        snd_als300_dbgplay("IRQ_PLAYBACK\n");
                }
        }
        if (status & IRQ_CAPTURE) {
                if (chip->pcm && chip->capture_substream) {
                        data = chip->capture_substream->runtime->private_data;
                        data->period_flipflop ^= 1;
                        snd_pcm_period_elapsed(chip->capture_substream);
                        snd_als300_dbgplay("IRQ_CAPTURE\n");
                }
        }
        return IRQ_HANDLED;
}

static irqreturn_t snd_als300plus_interrupt(int irq, void *dev_id)
{
        u8 general, mpu, dram;
        struct snd_als300 *chip = dev_id;
        struct snd_als300_substream_data *data;
        
        general = inb(chip->port+ALS300P_IRQ_STATUS);
        mpu = inb(chip->port+MPU_IRQ_STATUS);
        dram = inb(chip->port+ALS300P_DRAM_IRQ_STATUS);

        /* shared IRQ, for different device?? Exit ASAP! */
        if ((general == 0) && ((mpu & 0x80) == 0) && ((dram & 0x01) == 0))
                return IRQ_NONE;

        if (general & IRQ_PLAYBACK) {
                if (chip->pcm && chip->playback_substream) {
                        outb(IRQ_PLAYBACK, chip->port+ALS300P_IRQ_STATUS);
                        data = chip->playback_substream->runtime->private_data;
                        data->period_flipflop ^= 1;
                        snd_pcm_period_elapsed(chip->playback_substream);
                        snd_als300_dbgplay("IRQ_PLAYBACK\n");
                }
        }
        if (general & IRQ_CAPTURE) {
                if (chip->pcm && chip->capture_substream) {
                        outb(IRQ_CAPTURE, chip->port+ALS300P_IRQ_STATUS);
                        data = chip->capture_substream->runtime->private_data;
                        data->period_flipflop ^= 1;
                        snd_pcm_period_elapsed(chip->capture_substream);
                        snd_als300_dbgplay("IRQ_CAPTURE\n");
                }
        }
        /* FIXME: Ack other interrupt types. Not important right now as
         * those other devices aren't enabled. */
        return IRQ_HANDLED;
}

static unsigned short snd_als300_ac97_read(struct snd_ac97 *ac97,
                                                        unsigned short reg)
{
        int i;
        struct snd_als300 *chip = ac97->private_data;

        for (i = 0; i < 1000; i++) {
                if ((inb(chip->port+AC97_STATUS) & (AC97_BUSY)) == 0)
                        break;
                udelay(10);
        }
        outl((reg << 24) | (1 << 31), chip->port+AC97_ACCESS);

        for (i = 0; i < 1000; i++) {
                if ((inb(chip->port+AC97_STATUS) & (AC97_DATA_AVAIL)) != 0)
                        break;
                udelay(10);
        }
        return inw(chip->port+AC97_READ);
}

static void snd_als300_ac97_write(struct snd_ac97 *ac97,
                                unsigned short reg, unsigned short val)
{
        int i;
        struct snd_als300 *chip = ac97->private_data;

        for (i = 0; i < 1000; i++) {
                if ((inb(chip->port+AC97_STATUS) & (AC97_BUSY)) == 0)
                        break;
                udelay(10);
        }
        outl((reg << 24) | val, chip->port+AC97_ACCESS);
}

static int snd_als300_ac97(struct snd_als300 *chip)
{
        struct snd_ac97_bus *bus;
        struct snd_ac97_template ac97;
        int err;
        static const struct snd_ac97_bus_ops ops = {
                .write = snd_als300_ac97_write,
                .read = snd_als300_ac97_read,
        };

        err = snd_ac97_bus(chip->card, 0, &ops, NULL, &bus);
        if (err < 0)
                return err;

        memset(&ac97, 0, sizeof(ac97));
        ac97.private_data = chip;

        return snd_ac97_mixer(bus, &ac97, &chip->ac97);
}

/* hardware definition
 *
 * In AC97 mode, we always use 48k/16bit/stereo.
 * Any request to change data type is ignored by
 * the card when it is running outside of legacy
 * mode.
 */
static const struct snd_pcm_hardware snd_als300_playback_hw =
{
        .info =                 (SNDRV_PCM_INFO_MMAP |
                                SNDRV_PCM_INFO_INTERLEAVED |
                                SNDRV_PCM_INFO_PAUSE |
                                SNDRV_PCM_INFO_MMAP_VALID),
        .formats =              SNDRV_PCM_FMTBIT_S16,
        .rates =                SNDRV_PCM_RATE_48000,
        .rate_min =             48000,
        .rate_max =             48000,
        .channels_min =         2,
        .channels_max =         2,
        .buffer_bytes_max =     64 * 1024,
        .period_bytes_min =     64,
        .period_bytes_max =     32 * 1024,
        .periods_min =          2,
        .periods_max =          2,
};

static const struct snd_pcm_hardware snd_als300_capture_hw =
{
        .info =                 (SNDRV_PCM_INFO_MMAP |
                                SNDRV_PCM_INFO_INTERLEAVED |
                                SNDRV_PCM_INFO_PAUSE |
                                SNDRV_PCM_INFO_MMAP_VALID),
        .formats =              SNDRV_PCM_FMTBIT_S16,
        .rates =                SNDRV_PCM_RATE_48000,
        .rate_min =             48000,
        .rate_max =             48000,
        .channels_min =         2,
        .channels_max =         2,
        .buffer_bytes_max =     64 * 1024,
        .period_bytes_min =     64,
        .period_bytes_max =     32 * 1024,
        .periods_min =          2,
        .periods_max =          2,
};

static int snd_als300_playback_open(struct snd_pcm_substream *substream)
{
        struct snd_als300 *chip = snd_pcm_substream_chip(substream);
        struct snd_pcm_runtime *runtime = substream->runtime;
        struct snd_als300_substream_data *data = kzalloc_obj(*data);

        if (!data)
                return -ENOMEM;
        chip->playback_substream = substream;
        runtime->hw = snd_als300_playback_hw;
        runtime->private_data = data;
        data->control_register = PLAYBACK_CONTROL;
        data->block_counter_register = PLAYBACK_BLOCK_COUNTER;
        return 0;
}

static int snd_als300_playback_close(struct snd_pcm_substream *substream)
{
        struct snd_als300 *chip = snd_pcm_substream_chip(substream);
        struct snd_als300_substream_data *data;

        data = substream->runtime->private_data;
        kfree(data);
        chip->playback_substream = NULL;
        return 0;
}

static int snd_als300_capture_open(struct snd_pcm_substream *substream)
{
        struct snd_als300 *chip = snd_pcm_substream_chip(substream);
        struct snd_pcm_runtime *runtime = substream->runtime;
        struct snd_als300_substream_data *data = kzalloc_obj(*data);

        if (!data)
                return -ENOMEM;
        chip->capture_substream = substream;
        runtime->hw = snd_als300_capture_hw;
        runtime->private_data = data;
        data->control_register = RECORD_CONTROL;
        data->block_counter_register = RECORD_BLOCK_COUNTER;
        return 0;
}

static int snd_als300_capture_close(struct snd_pcm_substream *substream)
{
        struct snd_als300 *chip = snd_pcm_substream_chip(substream);
        struct snd_als300_substream_data *data;

        data = substream->runtime->private_data;
        kfree(data);
        chip->capture_substream = NULL;
        return 0;
}

static int snd_als300_playback_prepare(struct snd_pcm_substream *substream)
{
        u32 tmp;
        struct snd_als300 *chip = snd_pcm_substream_chip(substream);
        struct snd_pcm_runtime *runtime = substream->runtime;
        unsigned short period_bytes = snd_pcm_lib_period_bytes(substream);
        unsigned short buffer_bytes = snd_pcm_lib_buffer_bytes(substream);
        
        guard(spinlock_irq)(&chip->reg_lock);
        tmp = snd_als300_gcr_read(chip->port, PLAYBACK_CONTROL);
        tmp &= ~TRANSFER_START;

        snd_als300_dbgplay("Period bytes: %d Buffer bytes %d\n",
                                                period_bytes, buffer_bytes);
        
        /* set block size */
        tmp &= 0xffff0000;
        tmp |= period_bytes - 1;
        snd_als300_gcr_write(chip->port, PLAYBACK_CONTROL, tmp);

        /* set dma area */
        snd_als300_gcr_write(chip->port, PLAYBACK_START,
                                        runtime->dma_addr);
        snd_als300_gcr_write(chip->port, PLAYBACK_END,
                                        runtime->dma_addr + buffer_bytes - 1);
        return 0;
}

static int snd_als300_capture_prepare(struct snd_pcm_substream *substream)
{
        u32 tmp;
        struct snd_als300 *chip = snd_pcm_substream_chip(substream);
        struct snd_pcm_runtime *runtime = substream->runtime;
        unsigned short period_bytes = snd_pcm_lib_period_bytes(substream);
        unsigned short buffer_bytes = snd_pcm_lib_buffer_bytes(substream);

        guard(spinlock_irq)(&chip->reg_lock);
        tmp = snd_als300_gcr_read(chip->port, RECORD_CONTROL);
        tmp &= ~TRANSFER_START;

        snd_als300_dbgplay("Period bytes: %d Buffer bytes %d\n", period_bytes,
                                                        buffer_bytes);

        /* set block size */
        tmp &= 0xffff0000;
        tmp |= period_bytes - 1;

        /* set dma area */
        snd_als300_gcr_write(chip->port, RECORD_CONTROL, tmp);
        snd_als300_gcr_write(chip->port, RECORD_START,
                                        runtime->dma_addr);
        snd_als300_gcr_write(chip->port, RECORD_END,
                                        runtime->dma_addr + buffer_bytes - 1);
        return 0;
}

static int snd_als300_trigger(struct snd_pcm_substream *substream, int cmd)
{
        struct snd_als300 *chip = snd_pcm_substream_chip(substream);
        u32 tmp;
        struct snd_als300_substream_data *data;
        unsigned short reg;
        int ret = 0;

        data = substream->runtime->private_data;
        reg = data->control_register;

        guard(spinlock)(&chip->reg_lock);
        switch (cmd) {
        case SNDRV_PCM_TRIGGER_START:
        case SNDRV_PCM_TRIGGER_RESUME:
                tmp = snd_als300_gcr_read(chip->port, reg);
                data->period_flipflop = 1;
                snd_als300_gcr_write(chip->port, reg, tmp | TRANSFER_START);
                snd_als300_dbgplay("TRIGGER START\n");
                break;
        case SNDRV_PCM_TRIGGER_STOP:
        case SNDRV_PCM_TRIGGER_SUSPEND:
                tmp = snd_als300_gcr_read(chip->port, reg);
                snd_als300_gcr_write(chip->port, reg, tmp & ~TRANSFER_START);
                snd_als300_dbgplay("TRIGGER STOP\n");
                break;
        case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
                tmp = snd_als300_gcr_read(chip->port, reg);
                snd_als300_gcr_write(chip->port, reg, tmp | FIFO_PAUSE);
                snd_als300_dbgplay("TRIGGER PAUSE\n");
                break;
        case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
                tmp = snd_als300_gcr_read(chip->port, reg);
                snd_als300_gcr_write(chip->port, reg, tmp & ~FIFO_PAUSE);
                snd_als300_dbgplay("TRIGGER RELEASE\n");
                break;
        default:
                snd_als300_dbgplay("TRIGGER INVALID\n");
                ret = -EINVAL;
        }
        return ret;
}

static snd_pcm_uframes_t snd_als300_pointer(struct snd_pcm_substream *substream)
{
        u16 current_ptr;
        struct snd_als300 *chip = snd_pcm_substream_chip(substream);
        struct snd_als300_substream_data *data;
        unsigned short period_bytes;

        data = substream->runtime->private_data;
        period_bytes = snd_pcm_lib_period_bytes(substream);
        
        scoped_guard(spinlock, &chip->reg_lock) {
                current_ptr = (u16) snd_als300_gcr_read(chip->port,
                                                        data->block_counter_register) + 4;
        }
        if (current_ptr > period_bytes)
                current_ptr = 0;
        else
                current_ptr = period_bytes - current_ptr;

        if (data->period_flipflop == 0)
                current_ptr += period_bytes;
        snd_als300_dbgplay("Pointer (bytes): %d\n", current_ptr);
        return bytes_to_frames(substream->runtime, current_ptr);
}

static const struct snd_pcm_ops snd_als300_playback_ops = {
        .open =         snd_als300_playback_open,
        .close =        snd_als300_playback_close,
        .prepare =      snd_als300_playback_prepare,
        .trigger =      snd_als300_trigger,
        .pointer =      snd_als300_pointer,
};

static const struct snd_pcm_ops snd_als300_capture_ops = {
        .open =         snd_als300_capture_open,
        .close =        snd_als300_capture_close,
        .prepare =      snd_als300_capture_prepare,
        .trigger =      snd_als300_trigger,
        .pointer =      snd_als300_pointer,
};

static int snd_als300_new_pcm(struct snd_als300 *chip)
{
        struct snd_pcm *pcm;
        int err;

        err = snd_pcm_new(chip->card, "ALS300", 0, 1, 1, &pcm);
        if (err < 0)
                return err;
        pcm->private_data = chip;
        strscpy(pcm->name, "ALS300");
        chip->pcm = pcm;

        /* set operators */
        snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK,
                                &snd_als300_playback_ops);
        snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE,
                                &snd_als300_capture_ops);

        /* pre-allocation of buffers */
        snd_pcm_set_managed_buffer_all(pcm, SNDRV_DMA_TYPE_DEV, &chip->pci->dev,
                                       64*1024, 64*1024);
        return 0;
}

static void snd_als300_init(struct snd_als300 *chip)
{
        u32 tmp;
        
        guard(spinlock_irqsave)(&chip->reg_lock);
        chip->revision = (snd_als300_gcr_read(chip->port, MISC_CONTROL) >> 16)
                                                                & 0x0000000F;
        /* Setup DRAM */
        tmp = snd_als300_gcr_read(chip->port, DRAM_WRITE_CONTROL);
        snd_als300_gcr_write(chip->port, DRAM_WRITE_CONTROL,
                                                (tmp | DRAM_MODE_2)
                                                & ~WRITE_TRANS_START);

        /* Enable IRQ output */
        snd_als300_set_irq_flag(chip, IRQ_ENABLE);

        /* Unmute hardware devices so their outputs get routed to
         * the onboard mixer */
        tmp = snd_als300_gcr_read(chip->port, MISC_CONTROL);
        snd_als300_gcr_write(chip->port, MISC_CONTROL,
                        tmp | VMUTE_NORMAL | MMUTE_NORMAL);

        /* Reset volumes */
        snd_als300_gcr_write(chip->port, MUS_VOC_VOL, 0);

        /* Make sure playback transfer is stopped */
        tmp = snd_als300_gcr_read(chip->port, PLAYBACK_CONTROL);
        snd_als300_gcr_write(chip->port, PLAYBACK_CONTROL,
                        tmp & ~TRANSFER_START);
}

static int snd_als300_create(struct snd_card *card,
                             struct pci_dev *pci, int chip_type)
{
        struct snd_als300 *chip = card->private_data;
        void *irq_handler;
        int err;

        err = pcim_enable_device(pci);
        if (err < 0)
                return err;

        if (dma_set_mask_and_coherent(&pci->dev, DMA_BIT_MASK(28))) {
                dev_err(card->dev, "error setting 28bit DMA mask\n");
                return -ENXIO;
        }
        pci_set_master(pci);

        chip->card = card;
        chip->pci = pci;
        chip->irq = -1;
        chip->chip_type = chip_type;
        spin_lock_init(&chip->reg_lock);

        err = pcim_request_all_regions(pci, "ALS300");
        if (err < 0)
                return err;

        chip->port = pci_resource_start(pci, 0);

        if (chip->chip_type == DEVICE_ALS300_PLUS)
                irq_handler = snd_als300plus_interrupt;
        else
                irq_handler = snd_als300_interrupt;

        if (devm_request_irq(&pci->dev, pci->irq, irq_handler, IRQF_SHARED,
                             KBUILD_MODNAME, chip)) {
                dev_err(card->dev, "unable to grab IRQ %d\n", pci->irq);
                return -EBUSY;
        }
        chip->irq = pci->irq;
        card->sync_irq = chip->irq;
        card->private_free = snd_als300_free;

        snd_als300_init(chip);

        err = snd_als300_ac97(chip);
        if (err < 0) {
                dev_err(card->dev, "Could not create ac97\n");
                return err;
        }

        err = snd_als300_new_pcm(chip);
        if (err < 0) {
                dev_err(card->dev, "Could not create PCM\n");
                return err;
        }

        return 0;
}

static int snd_als300_suspend(struct device *dev)
{
        struct snd_card *card = dev_get_drvdata(dev);
        struct snd_als300 *chip = card->private_data;

        snd_power_change_state(card, SNDRV_CTL_POWER_D3hot);
        snd_ac97_suspend(chip->ac97);
        return 0;
}

static int snd_als300_resume(struct device *dev)
{
        struct snd_card *card = dev_get_drvdata(dev);
        struct snd_als300 *chip = card->private_data;

        snd_als300_init(chip);
        snd_ac97_resume(chip->ac97);

        snd_power_change_state(card, SNDRV_CTL_POWER_D0);
        return 0;
}

static DEFINE_SIMPLE_DEV_PM_OPS(snd_als300_pm, snd_als300_suspend, snd_als300_resume);

static int snd_als300_probe(struct pci_dev *pci,
                             const struct pci_device_id *pci_id)
{
        static int dev;
        struct snd_card *card;
        struct snd_als300 *chip;
        int err, chip_type;

        if (dev >= SNDRV_CARDS)
                return -ENODEV;
        if (!enable[dev]) {
                dev++;
                return -ENOENT;
        }

        err = snd_devm_card_new(&pci->dev, index[dev], id[dev], THIS_MODULE,
                                sizeof(*chip), &card);
        if (err < 0)
                return err;
        chip = card->private_data;

        chip_type = pci_id->driver_data;

        err = snd_als300_create(card, pci, chip_type);
        if (err < 0)
                goto error;

        strscpy(card->driver, "ALS300");
        if (chip->chip_type == DEVICE_ALS300_PLUS)
                /* don't know much about ALS300+ yet
                 * print revision number for now */
                sprintf(card->shortname, "ALS300+ (Rev. %d)", chip->revision);
        else
                sprintf(card->shortname, "ALS300 (Rev. %c)", 'A' +
                                                        chip->revision - 1);
        sprintf(card->longname, "%s at 0x%lx irq %i",
                                card->shortname, chip->port, chip->irq);

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

        pci_set_drvdata(pci, card);
        dev++;
        return 0;

 error:
        snd_card_free(card);
        return err;
}

static struct pci_driver als300_driver = {
        .name = KBUILD_MODNAME,
        .id_table = snd_als300_ids,
        .probe = snd_als300_probe,
        .driver = {
                .pm = &snd_als300_pm,
        },
};

module_pci_driver(als300_driver);