soundcard.c

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/*
 * linux/sound/oss/soundcard.c
 *
 * Sound card driver for Linux
 *
 *
 * 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)
 *                   integrated sound_switch.c
 * Stefan Reinauer   : integrated /proc/sound (equals to /dev/sndstat,
 *                   which should disappear in the near future)
 * Eric Dumas        : devfs support (22-Jan-98) <[email protected]> with
 *                   fixups by C. Scott Ananian <[email protected]>
 * Richard Gooch     : moved common (non OSS-specific) devices to sound_core.c
 * Rob Riggs         : Added persistent DMA buffers support (1998/10/17)
 * Christoph Hellwig : Some cleanup work (2000/03/01)
 */


#include "sound_config.h"
#include <linux/init.h>
#include <linux/types.h>
#include <linux/errno.h>
#include <linux/signal.h>
#include <linux/fcntl.h>
#include <linux/ctype.h>
#include <linux/stddef.h>
#include <linux/kmod.h>
#include <linux/kernel.h>
#include <asm/dma.h>
#include <asm/io.h>
#include <linux/wait.h>
#include <linux/ioport.h>
#include <linux/major.h>
#include <linux/delay.h>
#include <linux/proc_fs.h>
#include <linux/mutex.h>
#include <linux/module.h>
#include <linux/mm.h>
#include <linux/device.h>

/*
 * This ought to be moved into include/asm/dma.h
 */
#ifndef valid_dma
#define valid_dma(n) ((n) >= 0 && (n) < MAX_DMA_CHANNELS && (n) != 4)
#endif

/*
 * Table for permanently allocated memory (used when unloading the module)
 */
void *          sound_mem_blocks[MAX_MEM_BLOCKS];
static DEFINE_MUTEX(soundcard_mutex);
int             sound_nblocks = 0;

/* Persistent DMA buffers */
#ifdef CONFIG_SOUND_DMAP
int             sound_dmap_flag = 1;
#else
int             sound_dmap_flag = 0;
#endif

static char     dma_alloc_map[MAX_DMA_CHANNELS];

#define DMA_MAP_UNAVAIL     0
#define DMA_MAP_FREE        1
#define DMA_MAP_BUSY        2


unsigned long seq_time = 0; /* Time for /dev/sequencer */
extern struct class *sound_class;

/*
 * Table for configurable mixer volume handling
 */
static mixer_vol_table mixer_vols[MAX_MIXER_DEV];
static int num_mixer_volumes;

int *load_mixer_volumes(char *name, int *levels, int present)
{
    int             i, n;

    for (i = 0; i < num_mixer_volumes; i++) {
        if (strncmp(name, mixer_vols[i].name, 32) == 0) {
            if (present)
                mixer_vols[i].num = i;
            return mixer_vols[i].levels;
        }
    }
    if (num_mixer_volumes >= MAX_MIXER_DEV) {
        printk(KERN_ERR "Sound: Too many mixers (%s)\n", name);
        return levels;
    }
    n = num_mixer_volumes++;

    strncpy(mixer_vols[n].name, name, 32);

    if (present)
        mixer_vols[n].num = n;
    else
        mixer_vols[n].num = -1;

    for (i = 0; i < 32; i++)
        mixer_vols[n].levels[i] = levels[i];
    return mixer_vols[n].levels;
}
EXPORT_SYMBOL(load_mixer_volumes);

static int set_mixer_levels(void __user * arg)
{
        /* mixer_vol_table is 174 bytes, so IMHO no reason to not allocate it on the stack */
    mixer_vol_table buf;   

    if (__copy_from_user(&buf, arg, sizeof(buf)))
        return -EFAULT;
    load_mixer_volumes(buf.name, buf.levels, 0);
    if (__copy_to_user(arg, &buf, sizeof(buf)))
        return -EFAULT;
    return 0;
}

static int get_mixer_levels(void __user * arg)
{
    int n;

    if (__get_user(n, (int __user *)(&(((mixer_vol_table __user *)arg)->num))))
        return -EFAULT;
    if (n < 0 || n >= num_mixer_volumes)
        return -EINVAL;
    if (__copy_to_user(arg, &mixer_vols[n], sizeof(mixer_vol_table)))
        return -EFAULT;
    return 0;
}

/* 4K page size but our output routines use some slack for overruns */
#define PROC_BLOCK_SIZE (3*1024)

static ssize_t sound_read(struct file *file, char __user *buf, size_t count, loff_t *ppos)
{
    int dev = iminor(file->f_path.dentry->d_inode);
    int ret = -EINVAL;

    /*
     *  The OSS drivers aren't remotely happy without this locking,
     *  and unless someone fixes them when they are about to bite the
     *  big one anyway, we might as well bandage here..
     */
     
    mutex_lock(&soundcard_mutex);
    
    DEB(printk("sound_read(dev=%d, count=%d)\n", dev, count));
    switch (dev & 0x0f) {
    case SND_DEV_DSP:
    case SND_DEV_DSP16:
    case SND_DEV_AUDIO:
        ret = audio_read(dev, file, buf, count);
        break;

    case SND_DEV_SEQ:
    case SND_DEV_SEQ2:
        ret = sequencer_read(dev, file, buf, count);
        break;

    case SND_DEV_MIDIN:
        ret = MIDIbuf_read(dev, file, buf, count);
    }
    mutex_unlock(&soundcard_mutex);
    return ret;
}

static ssize_t sound_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos)
{
    int dev = iminor(file->f_path.dentry->d_inode);
    int ret = -EINVAL;
    
    mutex_lock(&soundcard_mutex);
    DEB(printk("sound_write(dev=%d, count=%d)\n", dev, count));
    switch (dev & 0x0f) {
    case SND_DEV_SEQ:
    case SND_DEV_SEQ2:
        ret =  sequencer_write(dev, file, buf, count);
        break;

    case SND_DEV_DSP:
    case SND_DEV_DSP16:
    case SND_DEV_AUDIO:
        ret = audio_write(dev, file, buf, count);
        break;

    case SND_DEV_MIDIN:
        ret =  MIDIbuf_write(dev, file, buf, count);
        break;
    }
    mutex_unlock(&soundcard_mutex);
    return ret;
}

static int sound_open(struct inode *inode, struct file *file)
{
    int dev = iminor(inode);
    int retval;

    DEB(printk("sound_open(dev=%d)\n", dev));
    if ((dev >= SND_NDEVS) || (dev < 0)) {
        printk(KERN_ERR "Invalid minor device %d\n", dev);
        return -ENXIO;
    }
    mutex_lock(&soundcard_mutex);
    switch (dev & 0x0f) {
    case SND_DEV_CTL:
        dev >>= 4;
        if (dev >= 0 && dev < MAX_MIXER_DEV && mixer_devs[dev] == NULL) {
            request_module("mixer%d", dev);
        }
        retval = -ENXIO;
        if (dev && (dev >= num_mixers || mixer_devs[dev] == NULL))
            break;
    
        if (!try_module_get(mixer_devs[dev]->owner))
            break;

        retval = 0;
        break;

    case SND_DEV_SEQ:
    case SND_DEV_SEQ2:
        retval = sequencer_open(dev, file);
        break;

    case SND_DEV_MIDIN:
        retval = MIDIbuf_open(dev, file);
        break;

    case SND_DEV_DSP:
    case SND_DEV_DSP16:
    case SND_DEV_AUDIO:
        retval = audio_open(dev, file);
        break;

    default:
        printk(KERN_ERR "Invalid minor device %d\n", dev);
        retval = -ENXIO;
    }

    mutex_unlock(&soundcard_mutex);
    return retval;
}

static int sound_release(struct inode *inode, struct file *file)
{
    int dev = iminor(inode);

    mutex_lock(&soundcard_mutex);
    DEB(printk("sound_release(dev=%d)\n", dev));
    switch (dev & 0x0f) {
    case SND_DEV_CTL:
        module_put(mixer_devs[dev >> 4]->owner);
        break;
        
    case SND_DEV_SEQ:
    case SND_DEV_SEQ2:
        sequencer_release(dev, file);
        break;

    case SND_DEV_MIDIN:
        MIDIbuf_release(dev, file);
        break;

    case SND_DEV_DSP:
    case SND_DEV_DSP16:
    case SND_DEV_AUDIO:
        audio_release(dev, file);
        break;

    default:
        printk(KERN_ERR "Sound error: Releasing unknown device 0x%02x\n", dev);
    }
    mutex_unlock(&soundcard_mutex);

    return 0;
}

static int get_mixer_info(int dev, void __user *arg)
{
    mixer_info info;
    memset(&info, 0, sizeof(info));
    strlcpy(info.id, mixer_devs[dev]->id, sizeof(info.id));
    strlcpy(info.name, mixer_devs[dev]->name, sizeof(info.name));
    info.modify_counter = mixer_devs[dev]->modify_counter;
    if (__copy_to_user(arg, &info,  sizeof(info)))
        return -EFAULT;
    return 0;
}

static int get_old_mixer_info(int dev, void __user *arg)
{
    _old_mixer_info info;
    memset(&info, 0, sizeof(info));
    strlcpy(info.id, mixer_devs[dev]->id, sizeof(info.id));
    strlcpy(info.name, mixer_devs[dev]->name, sizeof(info.name));
    if (copy_to_user(arg, &info,  sizeof(info)))
        return -EFAULT;
    return 0;
}

static int sound_mixer_ioctl(int mixdev, unsigned int cmd, void __user *arg)
{
    if (mixdev < 0 || mixdev >= MAX_MIXER_DEV)
        return -ENXIO;
    /* Try to load the mixer... */
    if (mixer_devs[mixdev] == NULL) {
        request_module("mixer%d", mixdev);
    }
    if (mixdev >= num_mixers || !mixer_devs[mixdev])
        return -ENXIO;
    if (cmd == SOUND_MIXER_INFO)
        return get_mixer_info(mixdev, arg);
    if (cmd == SOUND_OLD_MIXER_INFO)
        return get_old_mixer_info(mixdev, arg);
    if (_SIOC_DIR(cmd) & _SIOC_WRITE)
        mixer_devs[mixdev]->modify_counter++;
    if (!mixer_devs[mixdev]->ioctl)
        return -EINVAL;
    return mixer_devs[mixdev]->ioctl(mixdev, cmd, arg);
}

static long sound_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
    int len = 0, dtype;
    int dev = iminor(file->f_dentry->d_inode);
    long ret = -EINVAL;
    void __user *p = (void __user *)arg;

    if (_SIOC_DIR(cmd) != _SIOC_NONE && _SIOC_DIR(cmd) != 0) {
        /*
         * Have to validate the address given by the process.
         */
        len = _SIOC_SIZE(cmd);
        if (len < 1 || len > 65536 || !p)
            return -EFAULT;
        if (_SIOC_DIR(cmd) & _SIOC_WRITE)
            if (!access_ok(VERIFY_READ, p, len))
                return -EFAULT;
        if (_SIOC_DIR(cmd) & _SIOC_READ)
            if (!access_ok(VERIFY_WRITE, p, len))
                return -EFAULT;
    }
    DEB(printk("sound_ioctl(dev=%d, cmd=0x%x, arg=0x%x)\n", dev, cmd, arg));
    if (cmd == OSS_GETVERSION)
        return __put_user(SOUND_VERSION, (int __user *)p);
    
    mutex_lock(&soundcard_mutex);
    if (_IOC_TYPE(cmd) == 'M' && num_mixers > 0 &&   /* Mixer ioctl */
        (dev & 0x0f) != SND_DEV_CTL) {              
        dtype = dev & 0x0f;
        switch (dtype) {
        case SND_DEV_DSP:
        case SND_DEV_DSP16:
        case SND_DEV_AUDIO:
            ret = sound_mixer_ioctl(audio_devs[dev >> 4]->mixer_dev,
                         cmd, p);
            break;          
        default:
            ret = sound_mixer_ioctl(dev >> 4, cmd, p);
            break;
        }
        mutex_unlock(&soundcard_mutex);
        return ret;
    }

    switch (dev & 0x0f) {
    case SND_DEV_CTL:
        if (cmd == SOUND_MIXER_GETLEVELS)
            ret = get_mixer_levels(p);
        else if (cmd == SOUND_MIXER_SETLEVELS)
            ret = set_mixer_levels(p);
        else
            ret = sound_mixer_ioctl(dev >> 4, cmd, p);
        break;

    case SND_DEV_SEQ:
    case SND_DEV_SEQ2:
        ret = sequencer_ioctl(dev, file, cmd, p);
        break;

    case SND_DEV_DSP:
    case SND_DEV_DSP16:
    case SND_DEV_AUDIO:
        ret = audio_ioctl(dev, file, cmd, p);
        break;

    case SND_DEV_MIDIN:
        ret = MIDIbuf_ioctl(dev, file, cmd, p);
        break;

    }
    mutex_unlock(&soundcard_mutex);
    return ret;
}

static unsigned int sound_poll(struct file *file, poll_table * wait)
{
    struct inode *inode = file->f_path.dentry->d_inode;
    int dev = iminor(inode);

    DEB(printk("sound_poll(dev=%d)\n", dev));
    switch (dev & 0x0f) {
    case SND_DEV_SEQ:
    case SND_DEV_SEQ2:
        return sequencer_poll(dev, file, wait);

    case SND_DEV_MIDIN:
        return MIDIbuf_poll(dev, file, wait);

    case SND_DEV_DSP:
    case SND_DEV_DSP16:
    case SND_DEV_AUDIO:
        return DMAbuf_poll(file, dev >> 4, wait);
    }
    return 0;
}

static int sound_mmap(struct file *file, struct vm_area_struct *vma)
{
    int dev_class;
    unsigned long size;
    struct dma_buffparms *dmap = NULL;
    int dev = iminor(file->f_path.dentry->d_inode);

    dev_class = dev & 0x0f;
    dev >>= 4;

    if (dev_class != SND_DEV_DSP && dev_class != SND_DEV_DSP16 && dev_class != SND_DEV_AUDIO) {
        printk(KERN_ERR "Sound: mmap() not supported for other than audio devices\n");
        return -EINVAL;
    }
    mutex_lock(&soundcard_mutex);
    if (vma->vm_flags & VM_WRITE)   /* Map write and read/write to the output buf */
        dmap = audio_devs[dev]->dmap_out;
    else if (vma->vm_flags & VM_READ)
        dmap = audio_devs[dev]->dmap_in;
    else {
        printk(KERN_ERR "Sound: Undefined mmap() access\n");
        mutex_unlock(&soundcard_mutex);
        return -EINVAL;
    }

    if (dmap == NULL) {
        printk(KERN_ERR "Sound: mmap() error. dmap == NULL\n");
        mutex_unlock(&soundcard_mutex);
        return -EIO;
    }
    if (dmap->raw_buf == NULL) {
        printk(KERN_ERR "Sound: mmap() called when raw_buf == NULL\n");
        mutex_unlock(&soundcard_mutex);
        return -EIO;
    }
    if (dmap->mapping_flags) {
        printk(KERN_ERR "Sound: mmap() called twice for the same DMA buffer\n");
        mutex_unlock(&soundcard_mutex);
        return -EIO;
    }
    if (vma->vm_pgoff != 0) {
        printk(KERN_ERR "Sound: mmap() offset must be 0.\n");
        mutex_unlock(&soundcard_mutex);
        return -EINVAL;
    }
    size = vma->vm_end - vma->vm_start;

    if (size != dmap->bytes_in_use) {
        printk(KERN_WARNING "Sound: mmap() size = %ld. Should be %d\n", size, dmap->bytes_in_use);
    }
    if (remap_pfn_range(vma, vma->vm_start,
            virt_to_phys(dmap->raw_buf) >> PAGE_SHIFT,
            vma->vm_end - vma->vm_start, vma->vm_page_prot)) {
        mutex_unlock(&soundcard_mutex);
        return -EAGAIN;
    }

    dmap->mapping_flags |= DMA_MAP_MAPPED;

    if( audio_devs[dev]->d->mmap)
        audio_devs[dev]->d->mmap(dev);

    memset(dmap->raw_buf,
           dmap->neutral_byte,
           dmap->bytes_in_use);
    mutex_unlock(&soundcard_mutex);
    return 0;
}

const struct file_operations oss_sound_fops = {
    .owner      = THIS_MODULE,
    .llseek     = no_llseek,
    .read       = sound_read,
    .write      = sound_write,
    .poll       = sound_poll,
    .unlocked_ioctl = sound_ioctl,
    .mmap       = sound_mmap,
    .open       = sound_open,
    .release    = sound_release,
};

/*
 *  Create the required special subdevices
 */
 
static int create_special_devices(void)
{
    int seq1,seq2;
    seq1=register_sound_special(&oss_sound_fops, 1);
    if(seq1==-1)
        goto bad;
    seq2=register_sound_special(&oss_sound_fops, 8);
    if(seq2!=-1)
        return 0;
    unregister_sound_special(1);
bad:
    return -1;
}


static int dmabuf;
static int dmabug;

module_param(dmabuf, int, 0444);
module_param(dmabug, int, 0444);

/* additional minors for compatibility */
struct oss_minor_dev {
    unsigned short minor;
    unsigned int enabled;
} dev_list[] = {
    { SND_DEV_DSP16 },
    { SND_DEV_AUDIO },
};

static int __init oss_init(void)
{
    int             err;
    int i, j;
    
#ifdef CONFIG_PCI
    if(dmabug)
        isa_dma_bridge_buggy = dmabug;
#endif

    err = create_special_devices();
    if (err) {
        printk(KERN_ERR "sound: driver already loaded/included in kernel\n");
        return err;
    }

    /* Protecting the innocent */
    sound_dmap_flag = (dmabuf > 0 ? 1 : 0);

    for (i = 0; i < ARRAY_SIZE(dev_list); i++) {
        j = 0;
        do {
            unsigned short minor = dev_list[i].minor + j * 0x10;
            if (!register_sound_special(&oss_sound_fops, minor))
                dev_list[i].enabled = (1 << j);
        } while (++j < num_audiodevs);
    }

    if (sound_nblocks >= MAX_MEM_BLOCKS - 1)
        printk(KERN_ERR "Sound warning: Deallocation table was too small.\n");
    
    return 0;
}

static void __exit oss_cleanup(void)
{
    int i, j;

    for (i = 0; i < ARRAY_SIZE(dev_list); i++) {
        j = 0;
        do {
            if (dev_list[i].enabled & (1 << j))
                unregister_sound_special(dev_list[i].minor);
        } while (++j < num_audiodevs);
    }
    
    unregister_sound_special(1);
    unregister_sound_special(8);

    sound_stop_timer();

    sequencer_unload();

    for (i = 0; i < MAX_DMA_CHANNELS; i++)
        if (dma_alloc_map[i] != DMA_MAP_UNAVAIL) {
            printk(KERN_ERR "Sound: Hmm, DMA%d was left allocated - fixed\n", i);
            sound_free_dma(i);
        }

    for (i = 0; i < sound_nblocks; i++)
        vfree(sound_mem_blocks[i]);

}

module_init(oss_init);
module_exit(oss_cleanup);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("OSS Sound subsystem");
MODULE_AUTHOR("Hannu Savolainen, et al.");


int sound_alloc_dma(int chn, char *deviceID)
{
    int err;

    if ((err = request_dma(chn, deviceID)) != 0)
        return err;

    dma_alloc_map[chn] = DMA_MAP_FREE;

    return 0;
}
EXPORT_SYMBOL(sound_alloc_dma);

int sound_open_dma(int chn, char *deviceID)
{
    if (!valid_dma(chn)) {
        printk(KERN_ERR "sound_open_dma: Invalid DMA channel %d\n", chn);
        return 1;
    }

    if (dma_alloc_map[chn] != DMA_MAP_FREE) {
        printk("sound_open_dma: DMA channel %d busy or not allocated (%d)\n", chn, dma_alloc_map[chn]);
        return 1;
    }
    dma_alloc_map[chn] = DMA_MAP_BUSY;
    return 0;
}
EXPORT_SYMBOL(sound_open_dma);

void sound_free_dma(int chn)
{
    if (dma_alloc_map[chn] == DMA_MAP_UNAVAIL) {
        /* printk( "sound_free_dma: Bad access to DMA channel %d\n",  chn); */
        return;
    }
    free_dma(chn);
    dma_alloc_map[chn] = DMA_MAP_UNAVAIL;
}
EXPORT_SYMBOL(sound_free_dma);

void sound_close_dma(int chn)
{
    if (dma_alloc_map[chn] != DMA_MAP_BUSY) {
        printk(KERN_ERR "sound_close_dma: Bad access to DMA channel %d\n", chn);
        return;
    }
    dma_alloc_map[chn] = DMA_MAP_FREE;
}
EXPORT_SYMBOL(sound_close_dma);

static void do_sequencer_timer(unsigned long dummy)
{
    sequencer_timer(0);
}


static DEFINE_TIMER(seq_timer, do_sequencer_timer, 0, 0);

void request_sound_timer(int count)
{
    extern unsigned long seq_time;

    if (count < 0) {
        seq_timer.expires = (-count) + jiffies;
        add_timer(&seq_timer);
        return;
    }
    count += seq_time;

    count -= jiffies;

    if (count < 1)
        count = 1;

    seq_timer.expires = (count) + jiffies;
    add_timer(&seq_timer);
}

void sound_stop_timer(void)
{
    del_timer(&seq_timer);
}

void conf_printf(char *name, struct address_info *hw_config)
{
#ifndef CONFIG_SOUND_TRACEINIT
    return;
#else
    printk("<%s> at 0x%03x", name, hw_config->io_base);

    if (hw_config->irq)
        printk(" irq %d", (hw_config->irq > 0) ? hw_config->irq : -hw_config->irq);

    if (hw_config->dma != -1 || hw_config->dma2 != -1)
    {
        printk(" dma %d", hw_config->dma);
        if (hw_config->dma2 != -1)
            printk(",%d", hw_config->dma2);
    }
    printk("\n");
#endif
}
EXPORT_SYMBOL(conf_printf);

void conf_printf2(char *name, int base, int irq, int dma, int dma2)
{
#ifndef CONFIG_SOUND_TRACEINIT
    return;
#else
    printk("<%s> at 0x%03x", name, base);

    if (irq)
        printk(" irq %d", (irq > 0) ? irq : -irq);

    if (dma != -1 || dma2 != -1)
    {
          printk(" dma %d", dma);
          if (dma2 != -1)
              printk(",%d", dma2);
    }
    printk("\n");
#endif
}
EXPORT_SYMBOL(conf_printf2);