audio.c

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/*
 * sound/oss/audio.c
 *
 * Device file manager for /dev/audio
 */

/*
 * Copyright (C) by Hannu Savolainen 1993-1997
 *
 * OSS/Free for Linux is distributed under the GNU GENERAL PUBLIC LICENSE (GPL)
 * Version 2 (June 1991). See the "COPYING" file distributed with this software
 * for more info.
 */
/*
 * Thomas Sailer   : ioctl code reworked (vmalloc/vfree removed)
 * Thomas Sailer   : moved several static variables into struct audio_operations
 *                   (which is grossly misnamed btw.) because they have the same
 *                   lifetime as the rest in there and dynamic allocation saves
 *                   12k or so
 * Thomas Sailer   : use more logical O_NONBLOCK semantics
 * Daniel Rodriksson: reworked the use of the device specific copy_user
 *                    still generic
 * Horst von Brand:  Add missing #include <linux/string.h>
 * Chris Rankin    : Update the module-usage counter for the coprocessor,
 *                   and decrement the counters again if we cannot open
 *                   the audio device.
 */

#include <linux/stddef.h>
#include <linux/string.h>
#include <linux/kmod.h>

#include "sound_config.h"
#include "ulaw.h"
#include "coproc.h"

#define NEUTRAL8    0x80
#define NEUTRAL16   0x00


static int             dma_ioctl(int dev, unsigned int cmd, void __user *arg);

static int set_format(int dev, int fmt)
{
    if (fmt != AFMT_QUERY)
    {
        audio_devs[dev]->local_conversion = 0;

        if (!(audio_devs[dev]->format_mask & fmt))  /* Not supported */
        {
            if (fmt == AFMT_MU_LAW)
            {
                fmt = AFMT_U8;
                audio_devs[dev]->local_conversion = CNV_MU_LAW;
            }
            else
                fmt = AFMT_U8;  /* This is always supported */
        }
        audio_devs[dev]->audio_format = audio_devs[dev]->d->set_bits(dev, fmt);
        audio_devs[dev]->local_format = fmt;
    }
    else
        return audio_devs[dev]->local_format;

    if (audio_devs[dev]->local_conversion)
        return audio_devs[dev]->local_conversion;
    else 
        return audio_devs[dev]->local_format;
}

int audio_open(int dev, struct file *file)
{
    int ret;
    int bits;
    int dev_type = dev & 0x0f;
    int mode = translate_mode(file);
    const struct audio_driver *driver;
    const struct coproc_operations *coprocessor;

    dev = dev >> 4;

    if (dev_type == SND_DEV_DSP16)
        bits = 16;
    else
        bits = 8;

    if (dev < 0 || dev >= num_audiodevs)
        return -ENXIO;

    driver = audio_devs[dev]->d;

    if (!try_module_get(driver->owner))
        return -ENODEV;

    if ((ret = DMAbuf_open(dev, mode)) < 0)
        goto error_1;

    if ( (coprocessor = audio_devs[dev]->coproc) != NULL ) {
        if (!try_module_get(coprocessor->owner))
            goto error_2;

        if ((ret = coprocessor->open(coprocessor->devc, COPR_PCM)) < 0) {
            printk(KERN_WARNING "Sound: Can't access coprocessor device\n");
            goto error_3;
        }
    }
    
    audio_devs[dev]->local_conversion = 0;

    if (dev_type == SND_DEV_AUDIO)
        set_format(dev, AFMT_MU_LAW);
    else 
        set_format(dev, bits);

    audio_devs[dev]->audio_mode = AM_NONE;

    return 0;

    /*
     * Clean-up stack: this is what needs (un)doing if
     * we can't open the audio device ...
     */
    error_3:
    module_put(coprocessor->owner);

    error_2:
    DMAbuf_release(dev, mode);

    error_1:
    module_put(driver->owner);

    return ret;
}

static void sync_output(int dev)
{
    int             p, i;
    int             l;
    struct dma_buffparms *dmap = audio_devs[dev]->dmap_out;

    if (dmap->fragment_size <= 0)
        return;
    dmap->flags |= DMA_POST;

    /* Align the write pointer with fragment boundaries */
    
    if ((l = dmap->user_counter % dmap->fragment_size) > 0)
    {
        int len;
        unsigned long offs = dmap->user_counter % dmap->bytes_in_use;

        len = dmap->fragment_size - l;
        memset(dmap->raw_buf + offs, dmap->neutral_byte, len);
        DMAbuf_move_wrpointer(dev, len);
    }
    
    /*
     * Clean all unused buffer fragments.
     */

    p = dmap->qtail;
    dmap->flags |= DMA_POST;

    for (i = dmap->qlen + 1; i < dmap->nbufs; i++)
    {
        p = (p + 1) % dmap->nbufs;
        if (((dmap->raw_buf + p * dmap->fragment_size) + dmap->fragment_size) >
            (dmap->raw_buf + dmap->buffsize))
                printk(KERN_ERR "audio: Buffer error 2\n");

        memset(dmap->raw_buf + p * dmap->fragment_size,
            dmap->neutral_byte,
            dmap->fragment_size);
    }

    dmap->flags |= DMA_DIRTY;
}

void audio_release(int dev, struct file *file)
{
    const struct coproc_operations *coprocessor;
    int mode = translate_mode(file);

    dev = dev >> 4;

    /*
     * We do this in DMAbuf_release(). Why are we doing it
     * here? Why don't we test the file mode before setting
     * both flags? DMAbuf_release() does.
     * ...pester...pester...pester...
     */
    audio_devs[dev]->dmap_out->closing = 1;
    audio_devs[dev]->dmap_in->closing = 1;

    /*
     * We need to make sure we allocated the dmap_out buffer
     * before we go mucking around with it in sync_output().
     */
    if (mode & OPEN_WRITE)
        sync_output(dev);

    if ( (coprocessor = audio_devs[dev]->coproc) != NULL ) {
        coprocessor->close(coprocessor->devc, COPR_PCM);
        module_put(coprocessor->owner);
    }
    DMAbuf_release(dev, mode);

    module_put(audio_devs[dev]->d->owner);
}

static void translate_bytes(const unsigned char *table, unsigned char *buff, int n)
{
    unsigned long   i;

    if (n <= 0)
        return;

    for (i = 0; i < n; ++i)
        buff[i] = table[buff[i]];
}

int audio_write(int dev, struct file *file, const char __user *buf, int count)
{
    int c, p, l, buf_size, used, returned;
    int err;
    char *dma_buf;

    dev = dev >> 4;

    p = 0;
    c = count;
    
    if(count < 0)
        return -EINVAL;

    if (!(audio_devs[dev]->open_mode & OPEN_WRITE))
        return -EPERM;

    if (audio_devs[dev]->flags & DMA_DUPLEX)
        audio_devs[dev]->audio_mode |= AM_WRITE;
    else
        audio_devs[dev]->audio_mode = AM_WRITE;

    if (!count)     /* Flush output */
    {
          sync_output(dev);
          return 0;
    }
    
    while (c)
    {
        if ((err = DMAbuf_getwrbuffer(dev, &dma_buf, &buf_size, !!(file->f_flags & O_NONBLOCK))) < 0)
        {
                /* Handle nonblocking mode */
            if ((file->f_flags & O_NONBLOCK) && err == -EAGAIN)
                return p? p : -EAGAIN;  /* No more space. Return # of accepted bytes */
            return err;
        }
        l = c;

        if (l > buf_size)
            l = buf_size;

        returned = l;
        used = l;
        if (!audio_devs[dev]->d->copy_user)
        {
            if ((dma_buf + l) >
                (audio_devs[dev]->dmap_out->raw_buf + audio_devs[dev]->dmap_out->buffsize))
            {
                printk(KERN_ERR "audio: Buffer error 3 (%lx,%d), (%lx, %d)\n", (long) dma_buf, l, (long) audio_devs[dev]->dmap_out->raw_buf, (int) audio_devs[dev]->dmap_out->buffsize);
                return -EDOM;
            }
            if (dma_buf < audio_devs[dev]->dmap_out->raw_buf)
            {
                printk(KERN_ERR "audio: Buffer error 13 (%lx<%lx)\n", (long) dma_buf, (long) audio_devs[dev]->dmap_out->raw_buf);
                return -EDOM;
            }
            if(copy_from_user(dma_buf, &(buf)[p], l))
                return -EFAULT;
        } 
        else audio_devs[dev]->d->copy_user (dev,
                        dma_buf, 0,
                        buf, p,
                        c, buf_size,
                        &used, &returned,
                        l);
        l = returned;

        if (audio_devs[dev]->local_conversion & CNV_MU_LAW)
        {
            translate_bytes(ulaw_dsp, (unsigned char *) dma_buf, l);
        }
        c -= used;
        p += used;
        DMAbuf_move_wrpointer(dev, l);

    }

    return count;
}

int audio_read(int dev, struct file *file, char __user *buf, int count)
{
    int             c, p, l;
    char           *dmabuf;
    int             buf_no;

    dev = dev >> 4;
    p = 0;
    c = count;

    if (!(audio_devs[dev]->open_mode & OPEN_READ))
        return -EPERM;

    if ((audio_devs[dev]->audio_mode & AM_WRITE) && !(audio_devs[dev]->flags & DMA_DUPLEX))
        sync_output(dev);

    if (audio_devs[dev]->flags & DMA_DUPLEX)
        audio_devs[dev]->audio_mode |= AM_READ;
    else
        audio_devs[dev]->audio_mode = AM_READ;

    while(c)
    {
        if ((buf_no = DMAbuf_getrdbuffer(dev, &dmabuf, &l, !!(file->f_flags & O_NONBLOCK))) < 0)
        {
            /*
             *  Nonblocking mode handling. Return current # of bytes
             */

            if (p > 0)      /* Avoid throwing away data */
                return p;   /* Return it instead */

            if ((file->f_flags & O_NONBLOCK) && buf_no == -EAGAIN)
                return -EAGAIN;

            return buf_no;
        }
        if (l > c)
            l = c;

        /*
         * Insert any local processing here.
         */

        if (audio_devs[dev]->local_conversion & CNV_MU_LAW)
        {
            translate_bytes(dsp_ulaw, (unsigned char *) dmabuf, l);
        }
        
        {
            char           *fixit = dmabuf;

            if(copy_to_user(&(buf)[p], fixit, l))
                return -EFAULT;
        }

        DMAbuf_rmchars(dev, buf_no, l);

        p += l;
        c -= l;
    }

    return count - c;
}

int audio_ioctl(int dev, struct file *file, unsigned int cmd, void __user *arg)
{
    int val, count;
    unsigned long flags;
    struct dma_buffparms *dmap;
    int __user *p = arg;

    dev = dev >> 4;

    if (_IOC_TYPE(cmd) == 'C')  {
        if (audio_devs[dev]->coproc)    /* Coprocessor ioctl */
            return audio_devs[dev]->coproc->ioctl(audio_devs[dev]->coproc->devc, cmd, arg, 0);
        /* else
                printk(KERN_DEBUG"/dev/dsp%d: No coprocessor for this device\n", dev); */
        return -ENXIO;
    }
    else switch (cmd) 
    {
        case SNDCTL_DSP_SYNC:
            if (!(audio_devs[dev]->open_mode & OPEN_WRITE))
                return 0;
            if (audio_devs[dev]->dmap_out->fragment_size == 0)
                return 0;
            sync_output(dev);
            DMAbuf_sync(dev);
            DMAbuf_reset(dev);
            return 0;

        case SNDCTL_DSP_POST:
            if (!(audio_devs[dev]->open_mode & OPEN_WRITE))
                return 0;
            if (audio_devs[dev]->dmap_out->fragment_size == 0)
                return 0;
            audio_devs[dev]->dmap_out->flags |= DMA_POST | DMA_DIRTY;
            sync_output(dev);
            dma_ioctl(dev, SNDCTL_DSP_POST, NULL);
            return 0;

        case SNDCTL_DSP_RESET:
            audio_devs[dev]->audio_mode = AM_NONE;
            DMAbuf_reset(dev);
            return 0;

        case SNDCTL_DSP_GETFMTS:
            val = audio_devs[dev]->format_mask | AFMT_MU_LAW;
            break;
    
        case SNDCTL_DSP_SETFMT:
            if (get_user(val, p))
                return -EFAULT;
            val = set_format(dev, val);
            break;

        case SNDCTL_DSP_GETISPACE:
            if (!(audio_devs[dev]->open_mode & OPEN_READ))
                return 0;
            if ((audio_devs[dev]->audio_mode & AM_WRITE) && !(audio_devs[dev]->flags & DMA_DUPLEX))
                return -EBUSY;
            return dma_ioctl(dev, cmd, arg);

        case SNDCTL_DSP_GETOSPACE:
            if (!(audio_devs[dev]->open_mode & OPEN_WRITE))
                return -EPERM;
            if ((audio_devs[dev]->audio_mode & AM_READ) && !(audio_devs[dev]->flags & DMA_DUPLEX))
                return -EBUSY;
            return dma_ioctl(dev, cmd, arg);
        
        case SNDCTL_DSP_NONBLOCK:
            spin_lock(&file->f_lock);
            file->f_flags |= O_NONBLOCK;
            spin_unlock(&file->f_lock);
            return 0;

        case SNDCTL_DSP_GETCAPS:
                val = 1 | DSP_CAP_MMAP; /* Revision level of this ioctl() */
                if (audio_devs[dev]->flags & DMA_DUPLEX &&
                    audio_devs[dev]->open_mode == OPEN_READWRITE)
                    val |= DSP_CAP_DUPLEX;
                if (audio_devs[dev]->coproc)
                    val |= DSP_CAP_COPROC;
                if (audio_devs[dev]->d->local_qlen) /* Device has hidden buffers */
                    val |= DSP_CAP_BATCH;
                if (audio_devs[dev]->d->trigger)    /* Supports SETTRIGGER */
                    val |= DSP_CAP_TRIGGER;
                break;
            
        case SOUND_PCM_WRITE_RATE:
            if (get_user(val, p))
                return -EFAULT;
            val = audio_devs[dev]->d->set_speed(dev, val);
            break;

        case SOUND_PCM_READ_RATE:
            val = audio_devs[dev]->d->set_speed(dev, 0);
            break;
            
        case SNDCTL_DSP_STEREO:
            if (get_user(val, p))
                return -EFAULT;
            if (val > 1 || val < 0)
                return -EINVAL;
            val = audio_devs[dev]->d->set_channels(dev, val + 1) - 1;
            break;

        case SOUND_PCM_WRITE_CHANNELS:
            if (get_user(val, p))
                return -EFAULT;
            val = audio_devs[dev]->d->set_channels(dev, val);
            break;

        case SOUND_PCM_READ_CHANNELS:
            val = audio_devs[dev]->d->set_channels(dev, 0);
            break;
        
        case SOUND_PCM_READ_BITS:
            val = audio_devs[dev]->d->set_bits(dev, 0);
            break;

        case SNDCTL_DSP_SETDUPLEX:
            if (audio_devs[dev]->open_mode != OPEN_READWRITE)
                return -EPERM;
            return (audio_devs[dev]->flags & DMA_DUPLEX) ? 0 : -EIO;

        case SNDCTL_DSP_PROFILE:
            if (get_user(val, p))
                return -EFAULT;
            if (audio_devs[dev]->open_mode & OPEN_WRITE)
                audio_devs[dev]->dmap_out->applic_profile = val;
            if (audio_devs[dev]->open_mode & OPEN_READ)
                audio_devs[dev]->dmap_in->applic_profile = val;
            return 0;
        
        case SNDCTL_DSP_GETODELAY:
            dmap = audio_devs[dev]->dmap_out;
            if (!(audio_devs[dev]->open_mode & OPEN_WRITE))
                return -EINVAL;
            if (!(dmap->flags & DMA_ALLOC_DONE))
            {
                val=0;
                break;
            }
        
            spin_lock_irqsave(&dmap->lock,flags);
            /* Compute number of bytes that have been played */
            count = DMAbuf_get_buffer_pointer (dev, dmap, DMODE_OUTPUT);
            if (count < dmap->fragment_size && dmap->qhead != 0)
                count += dmap->bytes_in_use;    /* Pointer wrap not handled yet */
            count += dmap->byte_counter;
        
            /* Subtract current count from the number of bytes written by app */
            count = dmap->user_counter - count;
            if (count < 0)
                count = 0;
            spin_unlock_irqrestore(&dmap->lock,flags);
            val = count;
            break;
        
        default:
            return dma_ioctl(dev, cmd, arg);
    }
    return put_user(val, p);
}

void audio_init_devices(void)
{
    /*
     * NOTE! This routine could be called several times during boot.
     */
}

void reorganize_buffers(int dev, struct dma_buffparms *dmap, int recording)
{
    /*
     * This routine breaks the physical device buffers to logical ones.
     */

    struct audio_operations *dsp_dev = audio_devs[dev];

    unsigned i, n;
    unsigned sr, nc, sz, bsz;

    sr = dsp_dev->d->set_speed(dev, 0);
    nc = dsp_dev->d->set_channels(dev, 0);
    sz = dsp_dev->d->set_bits(dev, 0);

    if (sz == 8)
        dmap->neutral_byte = NEUTRAL8;
    else
        dmap->neutral_byte = NEUTRAL16;

    if (sr < 1 || nc < 1 || sz < 1)
    {
/*      printk(KERN_DEBUG "Warning: Invalid PCM parameters[%d] sr=%d, nc=%d, sz=%d\n", dev, sr, nc, sz);*/
        sr = DSP_DEFAULT_SPEED;
        nc = 1;
        sz = 8;
    }
    
    sz = sr * nc * sz;

    sz /= 8;        /* #bits -> #bytes */
    dmap->data_rate = sz;

    if (!dmap->needs_reorg)
        return;
    dmap->needs_reorg = 0;

    if (dmap->fragment_size == 0)
    {   
        /* Compute the fragment size using the default algorithm */

        /*
         * Compute a buffer size for time not exceeding 1 second.
         * Usually this algorithm gives a buffer size for 0.5 to 1.0 seconds
         * of sound (using the current speed, sample size and #channels).
         */

        bsz = dmap->buffsize;
        while (bsz > sz)
            bsz /= 2;

        if (bsz == dmap->buffsize)
            bsz /= 2;   /* Needs at least 2 buffers */

        /*
         *    Split the computed fragment to smaller parts. After 3.5a9
         *      the default subdivision is 4 which should give better
         *      results when recording.
         */

        if (dmap->subdivision == 0) /* Not already set */
        {
            dmap->subdivision = 4;  /* Init to the default value */

            if ((bsz / dmap->subdivision) > 4096)
                dmap->subdivision *= 2;
            if ((bsz / dmap->subdivision) < 4096)
                dmap->subdivision = 1;
        }
        bsz /= dmap->subdivision;

        if (bsz < 16)
            bsz = 16;   /* Just a sanity check */

        dmap->fragment_size = bsz;
    }
    else
    {
        /*
         * The process has specified the buffer size with SNDCTL_DSP_SETFRAGMENT or
         * the buffer size computation has already been done.
         */
        if (dmap->fragment_size > (dmap->buffsize / 2))
            dmap->fragment_size = (dmap->buffsize / 2);
        bsz = dmap->fragment_size;
    }

    if (audio_devs[dev]->min_fragment)
        if (bsz < (1 << audio_devs[dev]->min_fragment))
            bsz = 1 << audio_devs[dev]->min_fragment;
    if (audio_devs[dev]->max_fragment)
        if (bsz > (1 << audio_devs[dev]->max_fragment))
            bsz = 1 << audio_devs[dev]->max_fragment;
    bsz &= ~0x07;       /* Force size which is multiple of 8 bytes */
#ifdef OS_DMA_ALIGN_CHECK
    OS_DMA_ALIGN_CHECK(bsz);
#endif

    n = dmap->buffsize / bsz;
    if (n > MAX_SUB_BUFFERS)
        n = MAX_SUB_BUFFERS;
    if (n > dmap->max_fragments)
        n = dmap->max_fragments;

    if (n < 2)
    {
        n = 2;
        bsz /= 2;
    }
    dmap->nbufs = n;
    dmap->bytes_in_use = n * bsz;
    dmap->fragment_size = bsz;
    dmap->max_byte_counter = (dmap->data_rate * 60 * 60) +
            dmap->bytes_in_use; /* Approximately one hour */

    if (dmap->raw_buf)
    {
        memset(dmap->raw_buf, dmap->neutral_byte, dmap->bytes_in_use);
    }
    
    for (i = 0; i < dmap->nbufs; i++)
    {
        dmap->counts[i] = 0;
    }

    dmap->flags |= DMA_ALLOC_DONE | DMA_EMPTY;
}

static int dma_subdivide(int dev, struct dma_buffparms *dmap, int fact)
{
    if (fact == 0) 
    {
        fact = dmap->subdivision;
        if (fact == 0)
            fact = 1;
        return fact;
    }
    if (dmap->subdivision != 0 || dmap->fragment_size)  /* Too late to change */
        return -EINVAL;

    if (fact > MAX_REALTIME_FACTOR)
        return -EINVAL;

    if (fact != 1 && fact != 2 && fact != 4 && fact != 8 && fact != 16)
        return -EINVAL;

    dmap->subdivision = fact;
    return fact;
}

static int dma_set_fragment(int dev, struct dma_buffparms *dmap, int fact)
{
    int bytes, count;

    if (fact == 0)
        return -EIO;

    if (dmap->subdivision != 0 ||
        dmap->fragment_size)    /* Too late to change */
        return -EINVAL;

    bytes = fact & 0xffff;
    count = (fact >> 16) & 0x7fff;

    if (count == 0)
        count = MAX_SUB_BUFFERS;
    else if (count < MAX_SUB_BUFFERS)
        count++;

    if (bytes < 4 || bytes > 17)    /* <16 || > 512k */
        return -EINVAL;

    if (count < 2)
        return -EINVAL;

    if (audio_devs[dev]->min_fragment > 0)
        if (bytes < audio_devs[dev]->min_fragment)
            bytes = audio_devs[dev]->min_fragment;

    if (audio_devs[dev]->max_fragment > 0)
        if (bytes > audio_devs[dev]->max_fragment)
            bytes = audio_devs[dev]->max_fragment;

#ifdef OS_DMA_MINBITS
    if (bytes < OS_DMA_MINBITS)
        bytes = OS_DMA_MINBITS;
#endif

    dmap->fragment_size = (1 << bytes);
    dmap->max_fragments = count;

    if (dmap->fragment_size > dmap->buffsize)
        dmap->fragment_size = dmap->buffsize;

    if (dmap->fragment_size == dmap->buffsize &&
        audio_devs[dev]->flags & DMA_AUTOMODE)
        dmap->fragment_size /= 2;   /* Needs at least 2 buffers */

    dmap->subdivision = 1;  /* Disable SNDCTL_DSP_SUBDIVIDE */
    return bytes | ((count - 1) << 16);
}

static int dma_ioctl(int dev, unsigned int cmd, void __user *arg)
{
    struct dma_buffparms *dmap_out = audio_devs[dev]->dmap_out;
    struct dma_buffparms *dmap_in = audio_devs[dev]->dmap_in;
    struct dma_buffparms *dmap;
    audio_buf_info info;
    count_info cinfo;
    int fact, ret, changed, bits, count, err;
    unsigned long flags;

    switch (cmd) 
    {
        case SNDCTL_DSP_SUBDIVIDE:
            ret = 0;
            if (get_user(fact, (int __user *)arg))
                return -EFAULT;
            if (audio_devs[dev]->open_mode & OPEN_WRITE)
                ret = dma_subdivide(dev, dmap_out, fact);
            if (ret < 0)
                return ret;
            if (audio_devs[dev]->open_mode != OPEN_WRITE ||
                (audio_devs[dev]->flags & DMA_DUPLEX &&
                    audio_devs[dev]->open_mode & OPEN_READ))
                ret = dma_subdivide(dev, dmap_in, fact);
            if (ret < 0)
                return ret;
            break;

        case SNDCTL_DSP_GETISPACE:
        case SNDCTL_DSP_GETOSPACE:
            dmap = dmap_out;
            if (cmd == SNDCTL_DSP_GETISPACE && !(audio_devs[dev]->open_mode & OPEN_READ))
                return -EINVAL;
            if (cmd == SNDCTL_DSP_GETOSPACE && !(audio_devs[dev]->open_mode & OPEN_WRITE))
                return -EINVAL;
            if (cmd == SNDCTL_DSP_GETISPACE && audio_devs[dev]->flags & DMA_DUPLEX)
                dmap = dmap_in;
            if (dmap->mapping_flags & DMA_MAP_MAPPED)
                return -EINVAL;
            if (!(dmap->flags & DMA_ALLOC_DONE))
                reorganize_buffers(dev, dmap, (cmd == SNDCTL_DSP_GETISPACE));
            info.fragstotal = dmap->nbufs;
            if (cmd == SNDCTL_DSP_GETISPACE)
                info.fragments = dmap->qlen;
            else 
            {
                if (!DMAbuf_space_in_queue(dev))
                    info.fragments = 0;
                else
                {
                    info.fragments = DMAbuf_space_in_queue(dev);
                    if (audio_devs[dev]->d->local_qlen) 
                    {
                        int tmp = audio_devs[dev]->d->local_qlen(dev);
                        if (tmp && info.fragments)
                            tmp--;  /*
                                 * This buffer has been counted twice
                                 */
                        info.fragments -= tmp;
                    }
                }
            }
            if (info.fragments < 0)
                info.fragments = 0;
            else if (info.fragments > dmap->nbufs)
                info.fragments = dmap->nbufs;

            info.fragsize = dmap->fragment_size;
            info.bytes = info.fragments * dmap->fragment_size;

            if (cmd == SNDCTL_DSP_GETISPACE && dmap->qlen)
                info.bytes -= dmap->counts[dmap->qhead];
            else 
            {
                info.fragments = info.bytes / dmap->fragment_size;
                info.bytes -= dmap->user_counter % dmap->fragment_size;
            }
            if (copy_to_user(arg, &info, sizeof(info)))
                return -EFAULT;
            return 0;

        case SNDCTL_DSP_SETTRIGGER:
            if (get_user(bits, (int __user *)arg))
                return -EFAULT;
            bits &= audio_devs[dev]->open_mode;
            if (audio_devs[dev]->d->trigger == NULL)
                return -EINVAL;
            if (!(audio_devs[dev]->flags & DMA_DUPLEX) && (bits & PCM_ENABLE_INPUT) &&
                (bits & PCM_ENABLE_OUTPUT))
                return -EINVAL;

            if (bits & PCM_ENABLE_INPUT)
            {
                spin_lock_irqsave(&dmap_in->lock,flags);
                changed = (audio_devs[dev]->enable_bits ^ bits) & PCM_ENABLE_INPUT;
                if (changed && audio_devs[dev]->go) 
                {
                    reorganize_buffers(dev, dmap_in, 1);
                    if ((err = audio_devs[dev]->d->prepare_for_input(dev,
                             dmap_in->fragment_size, dmap_in->nbufs)) < 0) {
                        spin_unlock_irqrestore(&dmap_in->lock,flags);
                        return err;
                    }
                    dmap_in->dma_mode = DMODE_INPUT;
                    audio_devs[dev]->enable_bits |= PCM_ENABLE_INPUT;
                    DMAbuf_activate_recording(dev, dmap_in);
                } else
                    audio_devs[dev]->enable_bits &= ~PCM_ENABLE_INPUT;
                spin_unlock_irqrestore(&dmap_in->lock,flags);
            }
            if (bits & PCM_ENABLE_OUTPUT)
            {
                spin_lock_irqsave(&dmap_out->lock,flags);
                changed = (audio_devs[dev]->enable_bits ^ bits) & PCM_ENABLE_OUTPUT;
                if (changed &&
                    (dmap_out->mapping_flags & DMA_MAP_MAPPED || dmap_out->qlen > 0) &&
                    audio_devs[dev]->go) 
                {
                    if (!(dmap_out->flags & DMA_ALLOC_DONE))
                        reorganize_buffers(dev, dmap_out, 0);
                    dmap_out->dma_mode = DMODE_OUTPUT;
                    audio_devs[dev]->enable_bits |= PCM_ENABLE_OUTPUT;
                    dmap_out->counts[dmap_out->qhead] = dmap_out->fragment_size;
                    DMAbuf_launch_output(dev, dmap_out);
                } else
                    audio_devs[dev]->enable_bits &= ~PCM_ENABLE_OUTPUT;
                spin_unlock_irqrestore(&dmap_out->lock,flags);
            }
#if 0
            if (changed && audio_devs[dev]->d->trigger)
                audio_devs[dev]->d->trigger(dev, bits * audio_devs[dev]->go);
#endif              
            /* Falls through... */

        case SNDCTL_DSP_GETTRIGGER:
            ret = audio_devs[dev]->enable_bits;
            break;

        case SNDCTL_DSP_SETSYNCRO:
            if (!audio_devs[dev]->d->trigger)
                return -EINVAL;
            audio_devs[dev]->d->trigger(dev, 0);
            audio_devs[dev]->go = 0;
            return 0;

        case SNDCTL_DSP_GETIPTR:
            if (!(audio_devs[dev]->open_mode & OPEN_READ))
                return -EINVAL;
            spin_lock_irqsave(&dmap_in->lock,flags);
            cinfo.bytes = dmap_in->byte_counter;
            cinfo.ptr = DMAbuf_get_buffer_pointer(dev, dmap_in, DMODE_INPUT) & ~3;
            if (cinfo.ptr < dmap_in->fragment_size && dmap_in->qtail != 0)
                cinfo.bytes += dmap_in->bytes_in_use;   /* Pointer wrap not handled yet */
            cinfo.blocks = dmap_in->qlen;
            cinfo.bytes += cinfo.ptr;
            if (dmap_in->mapping_flags & DMA_MAP_MAPPED)
                dmap_in->qlen = 0;  /* Reset interrupt counter */
            spin_unlock_irqrestore(&dmap_in->lock,flags);
            if (copy_to_user(arg, &cinfo, sizeof(cinfo)))
                return -EFAULT;
            return 0;

        case SNDCTL_DSP_GETOPTR:
            if (!(audio_devs[dev]->open_mode & OPEN_WRITE))
                return -EINVAL;

            spin_lock_irqsave(&dmap_out->lock,flags);
            cinfo.bytes = dmap_out->byte_counter;
            cinfo.ptr = DMAbuf_get_buffer_pointer(dev, dmap_out, DMODE_OUTPUT) & ~3;
            if (cinfo.ptr < dmap_out->fragment_size && dmap_out->qhead != 0)
                cinfo.bytes += dmap_out->bytes_in_use;  /* Pointer wrap not handled yet */
            cinfo.blocks = dmap_out->qlen;
            cinfo.bytes += cinfo.ptr;
            if (dmap_out->mapping_flags & DMA_MAP_MAPPED)
                dmap_out->qlen = 0; /* Reset interrupt counter */
            spin_unlock_irqrestore(&dmap_out->lock,flags);
            if (copy_to_user(arg, &cinfo, sizeof(cinfo)))
                return -EFAULT;
            return 0;

        case SNDCTL_DSP_GETODELAY:
            if (!(audio_devs[dev]->open_mode & OPEN_WRITE))
                return -EINVAL;
            if (!(dmap_out->flags & DMA_ALLOC_DONE))
            {
                ret=0;
                break;
            }
            spin_lock_irqsave(&dmap_out->lock,flags);
            /* Compute number of bytes that have been played */
            count = DMAbuf_get_buffer_pointer (dev, dmap_out, DMODE_OUTPUT);
            if (count < dmap_out->fragment_size && dmap_out->qhead != 0)
                count += dmap_out->bytes_in_use;    /* Pointer wrap not handled yet */
            count += dmap_out->byte_counter;
            /* Subtract current count from the number of bytes written by app */
            count = dmap_out->user_counter - count;
            if (count < 0)
                count = 0;
            spin_unlock_irqrestore(&dmap_out->lock,flags);
            ret = count;
            break;

        case SNDCTL_DSP_POST:
            if (audio_devs[dev]->dmap_out->qlen > 0)
                if (!(audio_devs[dev]->dmap_out->flags & DMA_ACTIVE))
                    DMAbuf_launch_output(dev, audio_devs[dev]->dmap_out);
            return 0;

        case SNDCTL_DSP_GETBLKSIZE:
            dmap = dmap_out;
            if (audio_devs[dev]->open_mode & OPEN_WRITE)
                reorganize_buffers(dev, dmap_out, (audio_devs[dev]->open_mode == OPEN_READ));
            if (audio_devs[dev]->open_mode == OPEN_READ ||
                (audio_devs[dev]->flags & DMA_DUPLEX &&
                 audio_devs[dev]->open_mode & OPEN_READ))
                reorganize_buffers(dev, dmap_in, (audio_devs[dev]->open_mode == OPEN_READ));
            if (audio_devs[dev]->open_mode == OPEN_READ)
                dmap = dmap_in;
            ret = dmap->fragment_size;
            break;

        case SNDCTL_DSP_SETFRAGMENT:
            ret = 0;
            if (get_user(fact, (int __user *)arg))
                return -EFAULT;
            if (audio_devs[dev]->open_mode & OPEN_WRITE)
                ret = dma_set_fragment(dev, dmap_out, fact);
            if (ret < 0)
                return ret;
            if (audio_devs[dev]->open_mode == OPEN_READ ||
                (audio_devs[dev]->flags & DMA_DUPLEX &&
                 audio_devs[dev]->open_mode & OPEN_READ))
                ret = dma_set_fragment(dev, dmap_in, fact);
            if (ret < 0)
                return ret;
            if (!arg) /* don't know what this is good for, but preserve old semantics */
                return 0;
            break;

        default:
            if (!audio_devs[dev]->d->ioctl)
                return -EINVAL;
            return audio_devs[dev]->d->ioctl(dev, cmd, arg);
    }
    return put_user(ret, (int __user *)arg);
}