Merge with Linux 2.4.0-test5-pre3.

[linux-2.6/linux-mips.git] / drivers / sound / nm256_audio.c

/* 
 * Audio driver for the NeoMagic 256AV and 256ZX chipsets in native
 * mode, with AC97 mixer support.
 *
 * Overall design and parts of this code stolen from vidc_*.c and
 * skeleton.c.
 *
 * Yeah, there are a lot of magic constants in here.  You tell ME what
 * they are.  I just get this stuff psychically, remember? 
 *
 * This driver was written by someone who wishes to remain anonymous. 
 * It is in the public domain, so share and enjoy.  Try to make a profit
 * off of it; go on, I dare you.  
 */

#define __NO_VERSION__
#include <linux/pci.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/pm.h>
#include <linux/delay.h>
#include "sound_config.h"
#include "soundmodule.h"
#include "nm256.h"
#include "nm256_coeff.h"

int nm256_debug = 0;
static int force_load = 0;

/* 
 * The size of the playback reserve.  When the playback buffer has less
 * than NM256_PLAY_WMARK_SIZE bytes to output, we request a new
 * buffer.
 */
#define NM256_PLAY_WMARK_SIZE 512

static struct audio_driver nm256_audio_driver;

static int nm256_grabInterrupt (struct nm256_info *card);
static int nm256_releaseInterrupt (struct nm256_info *card);
static void nm256_interrupt (int irq, void *dev_id, struct pt_regs *dummy);
static void nm256_interrupt_zx (int irq, void *dev_id, struct pt_regs *dummy);
static int handle_pm_event (struct pm_dev *dev, pm_request_t rqst, void *data);

/* These belong in linux/pci.h. */
#define PCI_DEVICE_ID_NEOMAGIC_NM256AV_AUDIO 0x8005
#define PCI_DEVICE_ID_NEOMAGIC_NM256ZX_AUDIO 0x8006

#define RSRCADDRESS(dev,num) ((dev)->resource[(num)].start)

/* List of cards.  */
static struct nm256_info *nmcard_list;

/* Release the mapped-in memory for CARD.  */
static void
nm256_release_ports (struct nm256_info *card)
{
    int x;

    for (x = 0; x < 2; x++) {
        if (card->port[x].ptr != NULL) {
            u32 size = 
                card->port[x].end_offset - card->port[x].start_offset;
            release_region ((unsigned long) card->port[x].ptr, size);
            card->port[x].ptr = NULL;
        }
    }
}

/* 
 * Map in the memory ports for CARD, if they aren't already mapped in
 * and have been configured.  If successful, a zero value is returned;
 * otherwise any previously mapped-in areas are released and a non-zero
 * value is returned.
 *
 * This is invoked twice, once for each port.  Ideally it would only be
 * called once, but we now need to map in the second port in order to
 * check how much memory the card has on the 256ZX.
 */
static int
nm256_remap_ports (struct nm256_info *card)
{
    int x;

    for (x = 0; x < 2; x++) {
        if (card->port[x].ptr == NULL && card->port[x].end_offset > 0) {
            u32 physaddr 
                = card->port[x].physaddr + card->port[x].start_offset;
            u32 size 
                = card->port[x].end_offset - card->port[x].start_offset;

            card->port[x].ptr = ioremap_nocache (physaddr, size);
                                                  
            if (card->port[x].ptr == NULL) {
                printk (KERN_ERR "NM256: Unable to remap port %d\n", x + 1);
                nm256_release_ports (card);
                return -1;
            }
        }
    }
    return 0;
}

/* Locate the card in our list. */
static struct nm256_info *
nm256_find_card (int dev)
{
    struct nm256_info *card;

    for (card = nmcard_list; card != NULL; card = card->next_card)
        if (card->dev[0] == dev || card->dev[1] == dev)
            return card;

    return NULL;
}

/*
 * Ditto, but find the card struct corresponding to the mixer device DEV 
 * instead. 
 */
static struct nm256_info *
nm256_find_card_for_mixer (int dev)
{
    struct nm256_info *card;

    for (card = nmcard_list; card != NULL; card = card->next_card)
        if (card->mixer_oss_dev == dev)
            return card;

    return NULL;
}

static int usecache = 0;
static int buffertop = 0;

/* Check to see if we're using the bank of cached coefficients. */
int
nm256_cachedCoefficients (struct nm256_info *card)
{
    return usecache;
}

/* The actual rates supported by the card. */
static int samplerates[9] = {
    8000, 11025, 16000, 22050, 24000, 32000, 44100, 48000, 99999999
};

/*
 * Set the card samplerate, word size and stereo mode to correspond to
 * the settings in the CARD struct for the specified device in DEV.
 * We keep two separate sets of information, one for each device; the
 * hardware is not actually configured until a read or write is
 * attempted.
 */

int
nm256_setInfo (int dev, struct nm256_info *card)
{
    int x;
    int w;
    int targetrate;

    if (card->dev[0] == dev)
        w = 0;
    else if (card->dev[1] == dev)
        w = 1;
    else
        return -ENODEV;

    targetrate = card->sinfo[w].samplerate;

    if ((card->sinfo[w].bits != 8 && card->sinfo[w].bits != 16)
        || targetrate < samplerates[0]
        || targetrate > samplerates[7])
        return -EINVAL;

    for (x = 0; x < 8; x++)
        if (targetrate < ((samplerates[x] + samplerates[x + 1]) / 2))
            break;

    if (x < 8) {
        u8 ratebits = ((x << 4) & NM_RATE_MASK);
        if (card->sinfo[w].bits == 16)
            ratebits |= NM_RATE_BITS_16;
        if (card->sinfo[w].stereo)
            ratebits |= NM_RATE_STEREO;

        card->sinfo[w].samplerate = samplerates[x];


        if (card->dev_for_play == dev && card->playing) {
            if (nm256_debug)
                printk (KERN_DEBUG "Setting play ratebits to 0x%x\n",
                        ratebits);
            nm256_loadCoefficient (card, 0, x);
            nm256_writePort8 (card, 2,
                              NM_PLAYBACK_REG_OFFSET + NM_RATE_REG_OFFSET,
                              ratebits);
        }

        if (card->dev_for_record == dev && card->recording) {
            if (nm256_debug)
                printk (KERN_DEBUG "Setting record ratebits to 0x%x\n",
                        ratebits);
            nm256_loadCoefficient (card, 1, x);
            nm256_writePort8 (card, 2,
                              NM_RECORD_REG_OFFSET + NM_RATE_REG_OFFSET,
                              ratebits);
        }
        return 0;
    }
    else
        return -EINVAL;
}

/* Start the play process going. */
static void
startPlay (struct nm256_info *card)
{
    if (! card->playing) {
        card->playing = 1;
        if (nm256_grabInterrupt (card) == 0) {
            nm256_setInfo (card->dev_for_play, card);

            /* Enable playback engine and interrupts. */
            nm256_writePort8 (card, 2, NM_PLAYBACK_ENABLE_REG,
                              NM_PLAYBACK_ENABLE_FLAG | NM_PLAYBACK_FREERUN);

            /* Enable both channels. */
            nm256_writePort16 (card, 2, NM_AUDIO_MUTE_REG, 0x0);
        }
    }
}

/* 
 * Request one chunk of AMT bytes from the recording device.  When the
 * operation is complete, the data will be copied into BUFFER and the
 * function DMAbuf_inputintr will be invoked.
 */

static void
nm256_startRecording (struct nm256_info *card, char *buffer, u32 amt)
{
    u32 endpos;
    int enableEngine = 0;
    u32 ringsize = card->recordBufferSize;
    unsigned long flags;

    if (amt > (ringsize / 2)) {
        /*
         * Of course this won't actually work right, because the
         * caller is going to assume we will give what we got asked
         * for.
         */
        printk (KERN_ERR "NM256: Read request too large: %d\n", amt);
        amt = ringsize / 2;
    }

    if (amt < 8) {
        printk (KERN_ERR "NM256: Read request too small; %d\n", amt);
        return;
    }

    save_flags (flags);
    cli ();
    /*
     * If we're not currently recording, set up the start and end registers
     * for the recording engine.
     */
    if (! card->recording) {
        card->recording = 1;
        if (nm256_grabInterrupt (card) == 0) {
            card->curRecPos = 0;
            nm256_setInfo (card->dev_for_record, card);
            nm256_writePort32 (card, 2, NM_RBUFFER_START, card->abuf2);
            nm256_writePort32 (card, 2, NM_RBUFFER_END,
                                 card->abuf2 + ringsize);

            nm256_writePort32 (card, 2, NM_RBUFFER_CURRP,
                                 card->abuf2 + card->curRecPos);
            enableEngine = 1;
        }
        else {
            /* Not sure what else to do here.  */
            restore_flags (flags);
            return;
        }
    }

    /* 
     * If we happen to go past the end of the buffer a bit (due to a
     * delayed interrupt) it's OK.  So might as well set the watermark
     * right at the end of the data we want.
     */
    endpos = card->abuf2 + ((card->curRecPos + amt) % ringsize);

    card->recBuf = buffer;
    card->requestedRecAmt = amt;
    nm256_writePort32 (card, 2, NM_RBUFFER_WMARK, endpos);
    /* Enable recording engine and interrupts. */
    if (enableEngine)
        nm256_writePort8 (card, 2, NM_RECORD_ENABLE_REG,
                            NM_RECORD_ENABLE_FLAG | NM_RECORD_FREERUN);

    restore_flags (flags);
}

/* Stop the play engine. */
static void
stopPlay (struct nm256_info *card)
{
    /* Shut off sound from both channels. */
    nm256_writePort16 (card, 2, NM_AUDIO_MUTE_REG,
                       NM_AUDIO_MUTE_LEFT | NM_AUDIO_MUTE_RIGHT);
    /* Disable play engine. */
    nm256_writePort8 (card, 2, NM_PLAYBACK_ENABLE_REG, 0);
    if (card->playing) {
        nm256_releaseInterrupt (card);

        /* Reset the relevant state bits. */
        card->playing = 0;
        card->curPlayPos = 0;
    }
}

/* Stop recording. */
static void
stopRecord (struct nm256_info *card)
{
    /* Disable recording engine. */
    nm256_writePort8 (card, 2, NM_RECORD_ENABLE_REG, 0);

    if (card->recording) {
        nm256_releaseInterrupt (card);

        card->recording = 0;
        card->curRecPos = 0;
    }
}

/*
 * Ring buffers, man.  That's where the hip-hop, wild-n-wooly action's at.
 * 1972?  (Well, I suppose it was cheep-n-easy to implement.)
 *
 * Write AMT bytes of BUFFER to the playback ring buffer, and start the
 * playback engine running.  It will only accept up to 1/2 of the total
 * size of the ring buffer.  No check is made that we're about to overwrite
 * the currently-playing sample.
 */

static void
nm256_write_block (struct nm256_info *card, char *buffer, u32 amt)
{
    u32 ringsize = card->playbackBufferSize;
    u32 endstop;
    unsigned long flags;

    if (amt > (ringsize / 2)) {
        printk (KERN_ERR "NM256: Write request too large: %d\n", amt);
        amt = (ringsize / 2);
    }

    if (amt < NM256_PLAY_WMARK_SIZE) {
        printk (KERN_ERR "NM256: Write request too small: %d\n", amt);
        return;
    }

    card->curPlayPos %= ringsize;

    card->requested_amt = amt;

    save_flags (flags);
    cli ();

    if ((card->curPlayPos + amt) >= ringsize) {
        u32 rem = ringsize - card->curPlayPos;

        nm256_writeBuffer8 (card, buffer, 1,
                              card->abuf1 + card->curPlayPos,
                              rem);
        if (amt > rem)
            nm256_writeBuffer8 (card, buffer + rem, 1, card->abuf1,
                                  amt - rem);
    } 
    else
        nm256_writeBuffer8 (card, buffer, 1,
                              card->abuf1 + card->curPlayPos,
                              amt);

    /*
     * Setup the start-n-stop-n-limit registers, and start that engine
     * goin'. 
     *
     * Normally we just let it wrap around to avoid the click-click
     * action scene.
     */
    if (! card->playing) {
        /* The PBUFFER_END register in this case points to one sample
           before the end of the buffer. */
        int w = (card->dev_for_play == card->dev[0] ? 0 : 1);
        int sampsize = (card->sinfo[w].bits == 16 ? 2 : 1);

        if (card->sinfo[w].stereo)
            sampsize *= 2;

        /* Need to set the not-normally-changing-registers up. */
        nm256_writePort32 (card, 2, NM_PBUFFER_START,
                             card->abuf1 + card->curPlayPos);
        nm256_writePort32 (card, 2, NM_PBUFFER_END,
                             card->abuf1 + ringsize - sampsize);
        nm256_writePort32 (card, 2, NM_PBUFFER_CURRP,
                             card->abuf1 + card->curPlayPos);
    }
    endstop = (card->curPlayPos + amt - NM256_PLAY_WMARK_SIZE) % ringsize;
    nm256_writePort32 (card, 2, NM_PBUFFER_WMARK, card->abuf1 + endstop);

    if (! card->playing)
        startPlay (card);

    restore_flags (flags);
}

/*  We just got a card playback interrupt; process it.  */
static void
nm256_get_new_block (struct nm256_info *card)
{
    /* Check to see how much got played so far. */
    u32 amt = nm256_readPort32 (card, 2, NM_PBUFFER_CURRP) - card->abuf1;

    if (amt >= card->playbackBufferSize) {
        printk (KERN_ERR "NM256: Sound playback pointer invalid!\n");
        amt = 0;
    }

    if (amt < card->curPlayPos)
        amt = (card->playbackBufferSize - card->curPlayPos) + amt;
    else
        amt -= card->curPlayPos;

    if (card->requested_amt > (amt + NM256_PLAY_WMARK_SIZE)) {
        u32 endstop =
            card->curPlayPos + card->requested_amt - NM256_PLAY_WMARK_SIZE;
        nm256_writePort32 (card, 2, NM_PBUFFER_WMARK, card->abuf1 + endstop);
    } 
    else {
        card->curPlayPos += card->requested_amt;
        /* Get a new block to write.  This will eventually invoke
           nm256_write_block () or stopPlay ().  */
        DMAbuf_outputintr (card->dev_for_play, 1);
    }
}

/* Ultra cheez-whiz.  But I'm too lazy to grep headers. */
#define MIN(X,Y) ((X) < (Y) ? (X) : (Y))

/* 
 * Read the last-recorded block from the ring buffer, copy it into the
 * saved buffer pointer, and invoke DMAuf_inputintr() with the recording
 * device. 
 */

static void
nm256_read_block (struct nm256_info *card)
{
    /* Grab the current position of the recording pointer. */
    u32 currptr = nm256_readPort32 (card, 2, NM_RBUFFER_CURRP) - card->abuf2;
    u32 amtToRead = card->requestedRecAmt;
    u32 ringsize = card->recordBufferSize;

    if (currptr >= card->recordBufferSize) {
        printk (KERN_ERR "NM256: Sound buffer record pointer invalid!\n");
        currptr = 0;
    }

    /*
     * This test is probably redundant; we shouldn't be here unless
     * it's true.
     */
    if (card->recording) {
        /* If we wrapped around, copy everything from the start of our
           recording buffer to the end of the buffer. */
        if (currptr < card->curRecPos) {
            u32 amt = MIN (ringsize - card->curRecPos, amtToRead);

            nm256_readBuffer8 (card, card->recBuf, 1,
                                 card->abuf2 + card->curRecPos,
                                 amt);
            amtToRead -= amt;
            card->curRecPos += amt;
            card->recBuf += amt;
            if (card->curRecPos == ringsize)
                card->curRecPos = 0;
        }

        if ((card->curRecPos < currptr) && (amtToRead > 0)) {
            u32 amt = MIN (currptr - card->curRecPos, amtToRead);
            nm256_readBuffer8 (card, card->recBuf, 1,
                                 card->abuf2 + card->curRecPos, amt);
            card->curRecPos = ((card->curRecPos + amt) % ringsize);
        }
        card->recBuf = NULL;
        card->requestedRecAmt = 0;
        DMAbuf_inputintr (card->dev_for_record);
    }
}
#undef MIN

/* 
 * Initialize the hardware. 
 */
static void
nm256_initHw (struct nm256_info *card)
{
    /* Reset everything. */
    nm256_writePort8 (card, 2, 0x0, 0x11);
    nm256_writePort16 (card, 2, 0x214, 0);

    stopRecord (card);
    stopPlay (card);
}

/* 
 * Handle a potential interrupt for the device referred to by DEV_ID. 
 *
 * I don't like the cut-n-paste job here either between the two routines,
 * but there are sufficient differences between the two interrupt handlers
 * that parameterizing it isn't all that great either.  (Could use a macro,
 * I suppose...yucky bleah.)
 */

static void
nm256_interrupt (int irq, void *dev_id, struct pt_regs *dummy)
{
    struct nm256_info *card = (struct nm256_info *)dev_id;
    u16 status;
    static int badintrcount = 0;

    if ((card == NULL) || (card->magsig != NM_MAGIC_SIG)) {
        printk (KERN_ERR "NM256: Bad card pointer\n");
        return;
    }

    status = nm256_readPort16 (card, 2, NM_INT_REG);

    /* Not ours. */
    if (status == 0) {
        if (badintrcount++ > 1000) {
            /*
             * I'm not sure if the best thing is to stop the card from
             * playing or just release the interrupt (after all, we're in
             * a bad situation, so doing fancy stuff may not be such a good
             * idea).
             *
             * I worry about the card engine continuing to play noise
             * over and over, however--that could become a very
             * obnoxious problem.  And we know that when this usually
             * happens things are fairly safe, it just means the user's
             * inserted a PCMCIA card and someone's spamming us with IRQ 9s.
             */

            if (card->playing)
                stopPlay (card);
            if (card->recording)
                stopRecord (card);
            badintrcount = 0;
        }
        return;
    }

    badintrcount = 0;

    /* Rather boring; check for individual interrupts and process them. */

    if (status & NM_PLAYBACK_INT) {
        status &= ~NM_PLAYBACK_INT;
        NM_ACK_INT (card, NM_PLAYBACK_INT);

        if (card->playing)
            nm256_get_new_block (card);
    }

    if (status & NM_RECORD_INT) {
        status &= ~NM_RECORD_INT;
        NM_ACK_INT (card, NM_RECORD_INT);

        if (card->recording)
            nm256_read_block (card);
    }

    if (status & NM_MISC_INT_1) {
        u8 cbyte;

        status &= ~NM_MISC_INT_1;
        printk (KERN_ERR "NM256: Got misc interrupt #1\n");
        NM_ACK_INT (card, NM_MISC_INT_1);
        nm256_writePort16 (card, 2, NM_INT_REG, 0x8000);
        cbyte = nm256_readPort8 (card, 2, 0x400);
        nm256_writePort8 (card, 2, 0x400, cbyte | 2);
    }

    if (status & NM_MISC_INT_2) {
        u8 cbyte;

        status &= ~NM_MISC_INT_2;
        printk (KERN_ERR "NM256: Got misc interrupt #2\n");
        NM_ACK_INT (card, NM_MISC_INT_2);
        cbyte = nm256_readPort8 (card, 2, 0x400);
        nm256_writePort8 (card, 2, 0x400, cbyte & ~2);
    }

    /* Unknown interrupt. */
    if (status) {
        printk (KERN_ERR "NM256: Fire in the hole! Unknown status 0x%x\n",
                status);
        /* Pray. */
        NM_ACK_INT (card, status);
    }
}

/*
 * Handle a potential interrupt for the device referred to by DEV_ID.
 * This handler is for the 256ZX, and is very similar to the non-ZX
 * routine.
 */

static void
nm256_interrupt_zx (int irq, void *dev_id, struct pt_regs *dummy)
{
    struct nm256_info *card = (struct nm256_info *)dev_id;
    u32 status;
    static int badintrcount = 0;

    if ((card == NULL) || (card->magsig != NM_MAGIC_SIG)) {
        printk (KERN_ERR "NM256: Bad card pointer\n");
        return;
    }

    status = nm256_readPort32 (card, 2, NM_INT_REG);

    /* Not ours. */
    if (status == 0) {
        if (badintrcount++ > 1000) {
            printk (KERN_ERR "NM256: Releasing interrupt, over 1000 invalid interrupts\n");
            /*
             * I'm not sure if the best thing is to stop the card from
             * playing or just release the interrupt (after all, we're in
             * a bad situation, so doing fancy stuff may not be such a good
             * idea).
             *
             * I worry about the card engine continuing to play noise
             * over and over, however--that could become a very
             * obnoxious problem.  And we know that when this usually
             * happens things are fairly safe, it just means the user's
             * inserted a PCMCIA card and someone's spamming us with 
             * IRQ 9s.
             */

            if (card->playing)
                stopPlay (card);
            if (card->recording)
                stopRecord (card);
            badintrcount = 0;
        }
        return;
    }

    badintrcount = 0;

    /* Rather boring; check for individual interrupts and process them. */

    if (status & NM2_PLAYBACK_INT) {
        status &= ~NM2_PLAYBACK_INT;
        NM2_ACK_INT (card, NM2_PLAYBACK_INT);

        if (card->playing)
            nm256_get_new_block (card);
    }

    if (status & NM2_RECORD_INT) {
        status &= ~NM2_RECORD_INT;
        NM2_ACK_INT (card, NM2_RECORD_INT);

        if (card->recording)
            nm256_read_block (card);
    }

    if (status & NM2_MISC_INT_1) {
        u8 cbyte;

        status &= ~NM2_MISC_INT_1;
        printk (KERN_ERR "NM256: Got misc interrupt #1\n");
        NM2_ACK_INT (card, NM2_MISC_INT_1);
        cbyte = nm256_readPort8 (card, 2, 0x400);
        nm256_writePort8 (card, 2, 0x400, cbyte | 2);
    }

    if (status & NM2_MISC_INT_2) {
        u8 cbyte;

        status &= ~NM2_MISC_INT_2;
        printk (KERN_ERR "NM256: Got misc interrupt #2\n");
        NM2_ACK_INT (card, NM2_MISC_INT_2);
        cbyte = nm256_readPort8 (card, 2, 0x400);
        nm256_writePort8 (card, 2, 0x400, cbyte & ~2);
    }

    /* Unknown interrupt. */
    if (status) {
        printk (KERN_ERR "NM256: Fire in the hole! Unknown status 0x%x\n",
                status);
        /* Pray. */
        NM2_ACK_INT (card, status);
    }
}

/* 
 * Request our interrupt.
 */
static int
nm256_grabInterrupt (struct nm256_info *card)
{
    if (card->has_irq++ == 0) {
        if (request_irq (card->irq, card->introutine, SA_SHIRQ,
                         "NM256_audio", card) < 0) {
            printk (KERN_ERR "NM256: can't obtain IRQ %d\n", card->irq);
            return -1;
        }
    }
    return 0;
}

/* 
 * Release our interrupt. 
 */
static int
nm256_releaseInterrupt (struct nm256_info *card)
{
    if (card->has_irq <= 0) {
        printk (KERN_ERR "nm256: too many calls to releaseInterrupt\n");
        return -1;
    }
    card->has_irq--;
    if (card->has_irq == 0) {
        free_irq (card->irq, card);
    }
    return 0;
}

/*
 * Waits for the mixer to become ready to be written; returns a zero value
 * if it timed out.
 */

static int
nm256_isReady (struct ac97_hwint *dev)
{
    struct nm256_info *card = (struct nm256_info *)dev->driver_private;
    int t2 = 10;
    u32 testaddr;
    u16 testb;
    int done = 0;

    if (card->magsig != NM_MAGIC_SIG) {
        printk (KERN_ERR "NM256: Bad magic signature in isReady!\n");
        return 0;
    }

    testaddr = card->mixer_status_offset;
    testb = card->mixer_status_mask;

    /* 
     * Loop around waiting for the mixer to become ready. 
     */
    while (! done && t2-- > 0) {
        if ((nm256_readPort16 (card, 2, testaddr) & testb) == 0)
            done = 1;
        else
            udelay (100);
    }
    return done;
}

/*
 * Return the contents of the AC97 mixer register REG.  Returns a positive
 * value if successful, or a negative error code.
 */
static int
nm256_readAC97Reg (struct ac97_hwint *dev, u8 reg)
{
    struct nm256_info *card = (struct nm256_info *)dev->driver_private;

    if (card->magsig != NM_MAGIC_SIG) {
        printk (KERN_ERR "NM256: Bad magic signature in readAC97Reg!\n");
        return -EINVAL;
    }

    if (reg < 128) {
        int res;

        nm256_isReady (dev);
        res = nm256_readPort16 (card, 2, card->mixer + reg);
        /* Magic delay.  Bleah yucky.  */
        udelay (1000);
        return res;
    }
    else
        return -EINVAL;
}

/* 
 * Writes VALUE to AC97 mixer register REG.  Returns 0 if successful, or
 * a negative error code. 
 */
static int
nm256_writeAC97Reg (struct ac97_hwint *dev, u8 reg, u16 value)
{
    unsigned long flags;
    int tries = 2;
    int done = 0;
    u32 base;

    struct nm256_info *card = (struct nm256_info *)dev->driver_private;

    if (card->magsig != NM_MAGIC_SIG) {
        printk (KERN_ERR "NM256: Bad magic signature in writeAC97Reg!\n");
        return -EINVAL;
    }

    base = card->mixer;

    save_flags (flags);
    cli ();

    nm256_isReady (dev);

    /* Wait for the write to take, too. */
    while ((tries-- > 0) && !done) {
        nm256_writePort16 (card, 2, base + reg, value);
        if (nm256_isReady (dev)) {
            done = 1;
            break;
        }

    }

    restore_flags (flags);
    udelay (1000);

    return ! done;
}

/* 
 * Initial register values to be written to the AC97 mixer.
 * While most of these are identical to the reset values, we do this
 * so that we have most of the register contents cached--this avoids
 * reading from the mixer directly (which seems to be problematic,
 * probably due to ignorance).
 */
struct initialValues 
{
    unsigned short port;
    unsigned short value;
};

static struct initialValues nm256_ac97_initial_values[] = 
{
    { AC97_MASTER_VOL_STEREO, 0x8000 },
    { AC97_HEADPHONE_VOL,     0x8000 },
    { AC97_MASTER_VOL_MONO,   0x0000 },
    { AC97_PCBEEP_VOL,        0x0000 },
    { AC97_PHONE_VOL,         0x0008 },
    { AC97_MIC_VOL,           0x8000 },
    { AC97_LINEIN_VOL,        0x8808 },
    { AC97_CD_VOL,            0x8808 },
    { AC97_VIDEO_VOL,         0x8808 },
    { AC97_AUX_VOL,           0x8808 },
    { AC97_PCMOUT_VOL,        0x0808 },
    { AC97_RECORD_SELECT,     0x0000 },
    { AC97_RECORD_GAIN,       0x0B0B },
    { AC97_GENERAL_PURPOSE,   0x0000 },
    { 0xffff, 0xffff }
};

/* Initialize the AC97 into a known state.  */
static int
nm256_resetAC97 (struct ac97_hwint *dev)
{
    struct nm256_info *card = (struct nm256_info *)dev->driver_private;
    int x;

    if (card->magsig != NM_MAGIC_SIG) {
        printk (KERN_ERR "NM256: Bad magic signature in resetAC97!\n");
        return -EINVAL;
    }

    /* Reset the mixer.  'Tis magic!  */
    nm256_writePort8 (card, 2, 0x6c0, 1);
    nm256_writePort8 (card, 2, 0x6cc, 0x87);
    nm256_writePort8 (card, 2, 0x6cc, 0x80);
    nm256_writePort8 (card, 2, 0x6cc, 0x0);

    if (! card->mixer_values_init) {
        for (x = 0; nm256_ac97_initial_values[x].port != 0xffff; x++) {
            ac97_put_register (dev,
                               nm256_ac97_initial_values[x].port,
                               nm256_ac97_initial_values[x].value);
            card->mixer_values_init = 1;
        }
    }

    return 0;
}

/*
 * We don't do anything particularly special here; it just passes the
 * mixer ioctl to the AC97 driver.
 */
static int
nm256_default_mixer_ioctl (int dev, unsigned int cmd, caddr_t arg)
{
    struct nm256_info *card = nm256_find_card_for_mixer (dev);
    if (card != NULL)
        return ac97_mixer_ioctl (&(card->mdev), cmd, arg);
    else
        return -ENODEV;
}

static struct mixer_operations nm256_mixer_operations = {
    "NeoMagic",
    "NM256AC97Mixer",
    nm256_default_mixer_ioctl
};

/*
 * Default settings for the OSS mixer.  These are set last, after the
 * mixer is initialized.
 *
 * I "love" C sometimes.  Got braces?
 */
static struct ac97_mixer_value_list mixer_defaults[] = {
    { SOUND_MIXER_VOLUME,  { { 85, 85 } } },
    { SOUND_MIXER_SPEAKER, { { 100 } } },
    { SOUND_MIXER_PCM,     { { 65, 65 } } },
    { SOUND_MIXER_CD,      { { 65, 65 } } },
    { -1,                  {  { 0,  0 } } }
};


/* Installs the AC97 mixer into CARD.  */
static int
nm256_install_mixer (struct nm256_info *card)
{
    int mixer;

    card->mdev.reset_device = nm256_resetAC97;
    card->mdev.read_reg = nm256_readAC97Reg;
    card->mdev.write_reg = nm256_writeAC97Reg;
    card->mdev.driver_private = (void *)card;

    if (ac97_init (&(card->mdev)))
        return -1;

    mixer = sound_alloc_mixerdev();
    if (num_mixers >= MAX_MIXER_DEV) {
        printk ("NM256 mixer: Unable to alloc mixerdev\n");
        return -1;
    }

    mixer_devs[mixer] = &nm256_mixer_operations;
    card->mixer_oss_dev = mixer;

    /* Some reasonable default values.  */
    ac97_set_values (&(card->mdev), mixer_defaults);

    printk(KERN_INFO "Initialized AC97 mixer\n");
    return 0;
}

/* Perform a full reset on the hardware; this is invoked when an APM
   resume event occurs.  */
static void
nm256_full_reset (struct nm256_info *card)
{
    nm256_initHw (card);
    ac97_reset (&(card->mdev));
}

/* 
 * See if the signature left by the NM256 BIOS is intact; if so, we use
 * the associated address as the end of our audio buffer in the video
 * RAM.
 */

static void
nm256_peek_for_sig (struct nm256_info *card)
{
    u32 port1offset 
        = card->port[0].physaddr + card->port[0].end_offset - 0x0400;
    /* The signature is located 1K below the end of video RAM.  */
    char *temp = ioremap_nocache (port1offset, 16);
    /* Default buffer end is 5120 bytes below the top of RAM.  */
    u32 default_value = card->port[0].end_offset - 0x1400;
    u32 sig;

    /* Install the default value first, so we don't have to repeatedly
       do it if there is a problem.  */
    card->port[0].end_offset = default_value;

    if (temp == NULL) {
        printk (KERN_ERR "NM256: Unable to scan for card signature in video RAM\n");
        return;
    }
    sig = readl (temp);
    if ((sig & NM_SIG_MASK) == NM_SIGNATURE) {
        u32 pointer = readl (temp + 4);

        /*
         * If it's obviously invalid, don't use it (the port already has a
         * suitable default value set).
         */
        if (pointer != 0xffffffff)
            card->port[0].end_offset = pointer;

        printk (KERN_INFO "NM256: Found card signature in video RAM: 0x%x\n",
                pointer);
    }

    release_region ((unsigned long) temp, 16);
}

/* 
 * Install a driver for the PCI device referenced by PCIDEV.
 * VERSTR is a human-readable version string.
 */

static int
nm256_install(struct pci_dev *pcidev, enum nm256rev rev, char *verstr)
{
    struct nm256_info *card;
    struct pm_dev *pmdev;
    int x;

    card = kmalloc (sizeof (struct nm256_info), GFP_KERNEL);
    if (card == NULL) {
        printk (KERN_ERR "NM256: out of memory!\n");
        return 0;
    }

    card->magsig = NM_MAGIC_SIG;
    card->playing  = 0;
    card->recording = 0;
    card->rev = rev;

    /* Init the memory port info.  */
    for (x = 0; x < 2; x++) {
        card->port[x].physaddr = RSRCADDRESS (pcidev, x);
        card->port[x].ptr = NULL;
        card->port[x].start_offset = 0;
        card->port[x].end_offset = 0;
    }

    /* Port 2 is easy.  */
    card->port[1].start_offset = 0;
    card->port[1].end_offset = NM_PORT2_SIZE;

    /* Yuck.  But we have to map in port 2 so we can check how much RAM the
       card has.  */
    if (nm256_remap_ports (card)) {
        kfree (card);
        return 0;
    }

    /* 
     * The NM256 has two memory ports.  The first port is nothing
     * more than a chunk of video RAM, which is used as the I/O ring
     * buffer.  The second port has the actual juicy stuff (like the
     * mixer and the playback engine control registers).
     */

    if (card->rev == REV_NM256AV) {
        /* Ok, try to see if this is a non-AC97 version of the hardware. */
        int pval = nm256_readPort16 (card, 2, NM_MIXER_PRESENCE);
        if ((pval & NM_PRESENCE_MASK) != NM_PRESENCE_VALUE) {
            if (! force_load) {
                printk (KERN_ERR "NM256: This doesn't look to me like the AC97-compatible version.\n");
                printk (KERN_ERR "       You can force the driver to load by passing in the module\n");
                printk (KERN_ERR "       parameter:\n");
                printk (KERN_ERR "              force_ac97 = 1\n");
                printk (KERN_ERR "\n");
                printk (KERN_ERR "       More likely, you should be using the appropriate SB-16 or\n");
                printk (KERN_ERR "       CS4232 driver instead.  (If your BIOS has settings for\n");
                printk (KERN_ERR "       IRQ and/or DMA for the sound card, this is *not* the correct\n");
                printk (KERN_ERR "       driver to use.)\n");
                nm256_release_ports (card);
                kfree (card);
                return 0;
            }
            else {
                printk (KERN_INFO "NM256: Forcing driver load as per user request.\n");
            }
        }
        else {
         /*   printk (KERN_INFO "NM256: Congratulations. You're not running Eunice.\n")*/;
        }
        card->port[0].end_offset = 2560 * 1024;
        card->introutine = nm256_interrupt;
        card->mixer_status_offset = NM_MIXER_STATUS_OFFSET;
        card->mixer_status_mask = NM_MIXER_READY_MASK;
    } 
    else {
        /* Not sure if there is any relevant detect for the ZX or not.  */
        if (nm256_readPort8 (card, 2, 0xa0b) != 0)
            card->port[0].end_offset = 6144 * 1024;
        else
            card->port[0].end_offset = 4096 * 1024;

        card->introutine = nm256_interrupt_zx;
        card->mixer_status_offset = NM2_MIXER_STATUS_OFFSET;
        card->mixer_status_mask = NM2_MIXER_READY_MASK;
    }

    if (buffertop >= 98304 && buffertop < card->port[0].end_offset)
        card->port[0].end_offset = buffertop;
    else
        nm256_peek_for_sig (card);

    card->port[0].start_offset = card->port[0].end_offset - 98304;

    printk (KERN_INFO "NM256: Mapping port 1 from 0x%x - 0x%x\n",
            card->port[0].start_offset, card->port[0].end_offset);

    if (nm256_remap_ports (card)) {
        kfree (card);
        return 0;
    }

    /* See if we can get the interrupt. */

    card->irq = pcidev->irq;
    card->has_irq = 0;

    if (nm256_grabInterrupt (card) != 0) {
        nm256_release_ports (card);
        kfree (card);
        return 0;
    }

    nm256_releaseInterrupt (card);

    /*
     *  Init the board.
     */

    card->playbackBufferSize = 16384;
    card->recordBufferSize = 16384;

    card->coeffBuf = card->port[0].end_offset - NM_MAX_COEFFICIENT;
    card->abuf2 = card->coeffBuf - card->recordBufferSize;
    card->abuf1 = card->abuf2 - card->playbackBufferSize;
    card->allCoeffBuf = card->abuf2 - (NM_TOTAL_COEFF_COUNT * 4);

    /* Fixed setting. */
    card->mixer = NM_MIXER_OFFSET;
    card->mixer_values_init = 0;

    card->is_open_play = 0;
    card->is_open_record = 0;

    card->coeffsCurrent = 0;

    card->opencnt[0] = 0; card->opencnt[1] = 0;

    /* Reasonable default settings, but largely unnecessary. */
    for (x = 0; x < 2; x++) {
        card->sinfo[x].bits = 8;
        card->sinfo[x].stereo = 0;
        card->sinfo[x].samplerate = 8000;
    }

    nm256_initHw (card);

    for (x = 0; x < 2; x++) {
        if ((card->dev[x] =
             sound_install_audiodrv(AUDIO_DRIVER_VERSION,
                                    "NM256", &nm256_audio_driver,
                                    sizeof(struct audio_driver),
                                    DMA_NODMA, AFMT_U8 | AFMT_S16_LE,
                                    NULL, -1, -1)) >= 0) {
            /* 1K minimum buffer size. */
            audio_devs[card->dev[x]]->min_fragment = 10;
            /* Maximum of 8K buffer size. */
            audio_devs[card->dev[x]]->max_fragment = 13;
        }
        else {
            printk(KERN_ERR "NM256: Too many PCM devices available\n");
            nm256_release_ports (card);
            kfree (card);
            return 0;
        }
    }

    /* Insert the card in the list.  */
    card->next_card = nmcard_list;
    nmcard_list = card;

    printk(KERN_INFO "Initialized NeoMagic %s audio in PCI native mode\n",
           verstr);

    /* 
     * And our mixer.  (We should allow support for other mixers, maybe.)
     */

    nm256_install_mixer (card);

    pmdev = pm_register(PM_PCI_DEV, PM_PCI_ID(pcidev), handle_pm_event);
    if (pmdev)
        pmdev->data = card;

    return 1;
}


/*
 * PM event handler, so the card is properly reinitialized after a power
 * event.
 */
static int
handle_pm_event (struct pm_dev *dev, pm_request_t rqst, void *data)
{
    struct nm256_info *crd = (struct nm256_info*) dev->data;
    if (crd) {
        switch (rqst) {
        case PM_SUSPEND:
            break;
        case PM_RESUME:
            {
                int playing = crd->playing;
                nm256_full_reset (crd);
                /*
                 * A little ugly, but that's ok; pretend the
                 * block we were playing is done. 
                 */
                if (playing)
                    DMAbuf_outputintr (crd->dev_for_play, 1);
            }
            break;
        }
    }
    return 0;
}

/*
 *      This loop walks the PCI configuration database and finds where
 *      the sound cards are.
 */
 
int
init_nm256(void)
{
    struct pci_dev *pcidev = NULL;
    int count = 0;

    if(! pci_present())
        return -ENODEV;

    while((pcidev = pci_find_device(PCI_VENDOR_ID_NEOMAGIC,
                                    PCI_DEVICE_ID_NEOMAGIC_NM256AV_AUDIO,
                                    pcidev)) != NULL) {
        count += nm256_install(pcidev, REV_NM256AV, "256AV");
    }

    while((pcidev = pci_find_device(PCI_VENDOR_ID_NEOMAGIC,
                                    PCI_DEVICE_ID_NEOMAGIC_NM256ZX_AUDIO,
                                    pcidev)) != NULL) {
        count += nm256_install(pcidev, REV_NM256ZX, "256ZX");
    }

    if (count == 0)
        return -ENODEV;

    printk (KERN_INFO "Done installing NM256 audio driver.\n");
    return 0;
}

/*
 * Open the device
 *
 * DEV  - device
 * MODE - mode to open device (logical OR of OPEN_READ and OPEN_WRITE)
 *
 * Called when opening the DMAbuf               (dmabuf.c:259)
 */
static int
nm256_audio_open(int dev, int mode)
{
    struct nm256_info *card = nm256_find_card (dev);
    int w;
        
    if (card == NULL)
        return -ENODEV;

    if (card->dev[0] == dev)
        w = 0;
    else if (card->dev[1] == dev)
        w = 1;
    else
        return -ENODEV;

    if (card->opencnt[w] > 0)
        return -EBUSY;

    /* No bits set? Huh? */
    if (! ((mode & OPEN_READ) || (mode & OPEN_WRITE)))
        return -EIO;

    /*
     * If it's open for both read and write, and the card's currently
     * being read or written to, then do the opposite of what has
     * already been done.  Otherwise, don't specify any mode until the
     * user actually tries to do I/O.  (Some programs open the device
     * for both read and write, but only actually do reading or writing.)
     */

    if ((mode & OPEN_WRITE) && (mode & OPEN_READ)) {
        if (card->is_open_play)
            mode = OPEN_WRITE;
        else if (card->is_open_record)
            mode = OPEN_READ;
        else mode = 0;
    }
        
    if (mode & OPEN_WRITE) {
        if (card->is_open_play == 0) {
            card->dev_for_play = dev;
            card->is_open_play = 1;
        }
        else
            return -EBUSY;
    }

    if (mode & OPEN_READ) {
        if (card->is_open_record == 0) {
            card->dev_for_record = dev;
            card->is_open_record = 1;
        }
        else
            return -EBUSY;
    }

    card->opencnt[w]++;
    return 0;
}

/*
 * Close the device
 *
 * DEV  - device
 *
 * Called when closing the DMAbuf               (dmabuf.c:477)
 *      after halt_xfer
 */
static void
nm256_audio_close(int dev)
{
    struct nm256_info *card = nm256_find_card (dev);
        
    if (card != NULL) {
        int w;

        if (card->dev[0] == dev)
            w = 0;
        else if (card->dev[1] == dev)
            w = 1;
        else
            return;

        card->opencnt[w]--;
        if (card->opencnt[w] <= 0) {
            card->opencnt[w] = 0;

            if (card->dev_for_play == dev) {
                stopPlay (card);
                card->is_open_play = 0;
                card->dev_for_play = -1;
            }

            if (card->dev_for_record == dev) {
                stopRecord (card);
                card->is_open_record = 0;
                card->dev_for_record = -1;
            }
        }
    }
}

/* Standard ioctl handler. */
static int
nm256_audio_ioctl(int dev, unsigned int cmd, caddr_t arg)
{
    int ret;
    u32 oldinfo;
    int w;

    struct nm256_info *card = nm256_find_card (dev);

    if (card == NULL)
        return -ENODEV;

    if (dev == card->dev[0])
        w = 0;
    else
        w = 1;

    /* 
     * The code here is messy.  There are probably better ways to do
     * it.  (It should be possible to handle it the same way the AC97 mixer 
     * is done.)
     */
    switch (cmd)
        {
        case SOUND_PCM_WRITE_RATE:
            get_user_ret(ret, (int *) arg, -EFAULT);

            if (ret != 0) {
                oldinfo = card->sinfo[w].samplerate;
                card->sinfo[w].samplerate = ret;
                ret = nm256_setInfo(dev, card);
                if (ret != 0)
                    card->sinfo[w].samplerate = oldinfo;
            }
            if (ret == 0)
                ret = card->sinfo[w].samplerate;
            break;

        case SOUND_PCM_READ_RATE:
            ret = card->sinfo[w].samplerate;
            break;

        case SNDCTL_DSP_STEREO:
            get_user_ret(ret, (int *) arg, -EFAULT);

            card->sinfo[w].stereo = ret ? 1 : 0;
            ret = nm256_setInfo (dev, card);
            if (ret == 0)
                ret = card->sinfo[w].stereo;

            break;

        case SOUND_PCM_WRITE_CHANNELS:
            get_user_ret(ret, (int *) arg, -EFAULT);

            if (ret < 1 || ret > 3)
                ret = card->sinfo[w].stereo + 1;
            else {
                card->sinfo[w].stereo = ret - 1;
                ret = nm256_setInfo (dev, card);
                if (ret == 0)
                    ret = card->sinfo[w].stereo + 1;
            }
            break;

        case SOUND_PCM_READ_CHANNELS:
            ret = card->sinfo[w].stereo + 1;
            break;

        case SNDCTL_DSP_SETFMT:
            get_user_ret(ret, (int *) arg, -EFAULT);

            if (ret != 0) {
                oldinfo = card->sinfo[w].bits;
                card->sinfo[w].bits = ret;
                ret = nm256_setInfo (dev, card);
                if (ret != 0)
                    card->sinfo[w].bits = oldinfo;
            }
            if (ret == 0)
                ret = card->sinfo[w].bits;
            break;

        case SOUND_PCM_READ_BITS:
            ret = card->sinfo[w].bits;
            break;

        default:
            return -EINVAL;
        }
    return put_user(ret, (int *) arg);
}

/*
 * Given the sound device DEV and an associated physical buffer PHYSBUF, 
 * return a pointer to the actual buffer in kernel space. 
 *
 * This routine should exist as part of the soundcore routines.
 */

static char *
nm256_getDMAbuffer (int dev, unsigned long physbuf)
{
    struct audio_operations *adev = audio_devs[dev];
    struct dma_buffparms *dmap = adev->dmap_out;
    char *dma_start =
        (char *)(physbuf - (unsigned long)dmap->raw_buf_phys 
                 + (unsigned long)dmap->raw_buf);

    return dma_start;
}


/*
 * Output a block to sound device
 *
 * dev          - device number
 * buf          - physical address of buffer
 * total_count  - total byte count in buffer
 * intrflag     - set if this has been called from an interrupt 
 *                                (via DMAbuf_outputintr)
 * restart_dma  - set if engine needs to be re-initialised
 *
 * Called when:
 *  1. Starting output                                  (dmabuf.c:1327)
 *  2.                                                  (dmabuf.c:1504)
 *  3. A new buffer needs to be sent to the device      (dmabuf.c:1579)
 */
static void
nm256_audio_output_block(int dev, unsigned long physbuf,
                                       int total_count, int intrflag)
{
    struct nm256_info *card = nm256_find_card (dev);

    if (card != NULL) {
        char *dma_buf = nm256_getDMAbuffer (dev, physbuf);
        card->is_open_play = 1;
        card->dev_for_play = dev;
        nm256_write_block (card, dma_buf, total_count);
    }
}

/* Ditto, but do recording instead.  */
static void
nm256_audio_start_input(int dev, unsigned long physbuf, int count,
                        int intrflag)
{
    struct nm256_info *card = nm256_find_card (dev);

    if (card != NULL) {
        char *dma_buf = nm256_getDMAbuffer (dev, physbuf);
        card->is_open_record = 1;
        card->dev_for_record = dev;
        nm256_startRecording (card, dma_buf, count);
    }
}

/* 
 * Prepare for inputting samples to DEV. 
 * Each requested buffer will be BSIZE byes long, with a total of
 * BCOUNT buffers. 
 */

static int
nm256_audio_prepare_for_input(int dev, int bsize, int bcount)
{
    struct nm256_info *card = nm256_find_card (dev);

    if (card == NULL) 
        return -ENODEV;

    if (card->is_open_record && card->dev_for_record != dev)
        return -EBUSY;

    audio_devs[dev]->dmap_in->flags |= DMA_NODMA;
    return 0;
}

/*
 * Prepare for outputting samples to `dev'
 *
 * Each buffer that will be passed will be `bsize' bytes long,
 * with a total of `bcount' buffers.
 *
 * Called when:
 *  1. A trigger enables audio output                   (dmabuf.c:978)
 *  2. We get a write buffer without dma_mode setup     (dmabuf.c:1152)
 *  3. We restart a transfer                            (dmabuf.c:1324)
 */

static int
nm256_audio_prepare_for_output(int dev, int bsize, int bcount)
{
    struct nm256_info *card = nm256_find_card (dev);

    if (card == NULL)
        return -ENODEV;

    if (card->is_open_play && card->dev_for_play != dev)
        return -EBUSY;

    audio_devs[dev]->dmap_out->flags |= DMA_NODMA;
    return 0;
}

/* Stop the current operations associated with DEV.  */
static void
nm256_audio_reset(int dev)
{
    struct nm256_info *card = nm256_find_card (dev);

    if (card != NULL) {
        if (card->dev_for_play == dev)
            stopPlay (card);
        if (card->dev_for_record == dev)
            stopRecord (card);
    }
}

static int
nm256_audio_local_qlen(int dev)
{
    return 0;
}

static struct audio_driver nm256_audio_driver =
{
    nm256_audio_open,                   /* open                 */
    nm256_audio_close,                  /* close                */
    nm256_audio_output_block,           /* output_block         */
    nm256_audio_start_input,            /* start_input          */
    nm256_audio_ioctl,                  /* ioctl                */
    nm256_audio_prepare_for_input,      /* prepare_for_input    */
    nm256_audio_prepare_for_output,     /* prepare_for_output   */
    nm256_audio_reset,                  /* reset                */
    nm256_audio_local_qlen,             /*+local_qlen           */
    NULL,                               /*+copy_from_user       */
    NULL,                               /*+halt_input           */
    NULL,                               /* halt_output          */
    NULL,                               /*+trigger              */
    NULL,                               /*+set_speed            */
    NULL,                               /*+set_bits             */
    NULL,                               /*+set_channels         */
};

EXPORT_SYMBOL(init_nm256);

static int loaded = 0;

MODULE_PARM (usecache, "i");
MODULE_PARM (buffertop, "i");
MODULE_PARM (nm256_debug, "i");
MODULE_PARM (force_load, "i");

static int __init do_init_nm256(void)
{
    nmcard_list = NULL;
    printk (KERN_INFO "NeoMagic 256AV/256ZX audio driver, version 1.1\n");

    if (init_nm256 () == 0) {
        SOUND_LOCK;
        loaded = 1;
        return 0;
    }
    else
        return -ENODEV;
}

static void __exit cleanup_nm256 (void)
{
    if (loaded) {
        struct nm256_info *card;
        struct nm256_info *next_card;

        SOUND_LOCK_END;

        for (card = nmcard_list; card != NULL; card = next_card) {
            stopPlay (card);
            stopRecord (card);
            if (card->has_irq)
                free_irq (card->irq, card);
            nm256_release_ports (card);
            sound_unload_mixerdev (card->mixer_oss_dev);
            sound_unload_audiodev (card->dev[0]);
            sound_unload_audiodev (card->dev[1]);
            next_card = card->next_card;
            kfree (card);
        }
        nmcard_list = NULL;
    }
    pm_unregister_all (&handle_pm_event);
}

module_init(do_init_nm256);
module_exit(cleanup_nm256);

/*
 * Local variables:
 *  c-basic-offset: 4
 * End:
 */