soundcard.c

linux 内核源代码

			return get_mixer_levels(p);
		if (cmd == SOUND_MIXER_SETLEVELS)
			return set_mixer_levels(p);
		return sound_mixer_ioctl(dev >> 4, cmd, p);

	case SND_DEV_SEQ:
	case SND_DEV_SEQ2:
		return sequencer_ioctl(dev, file, cmd, p);

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

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

	}
	return -EINVAL;
}

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;
	}
	lock_kernel();
	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");
		unlock_kernel();
		return -EINVAL;
	}

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

const struct file_operations oss_sound_fops = {
	.owner		= THIS_MODULE,
	.llseek		= no_llseek,
	.read		= sound_read,
	.write		= sound_write,
	.poll		= sound_poll,
	.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;
}


/* These device names follow the official Linux device list,
 * Documentation/devices.txt.  Let us know if there are other
 * common names we should support for compatibility.
 * Only those devices not created by the generic code in sound_core.c are
 * registered here.
 */
static const struct {
	unsigned short minor;
	char *name;
	umode_t mode;
	int *num;
} dev_list[] = { /* list of minor devices */
/* seems to be some confusion here -- this device is not in the device list */
	{SND_DEV_DSP16,     "dspW",	 S_IWUGO | S_IRUSR | S_IRGRP,
	 &num_audiodevs},
	{SND_DEV_AUDIO,     "audio",	 S_IWUGO | S_IRUSR | S_IRGRP,
	 &num_audiodevs},
};

static int dmabuf;
static int dmabug;

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

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++) {
		device_create(sound_class, NULL,
			      MKDEV(SOUND_MAJOR, dev_list[i].minor),
			      "%s", dev_list[i].name);

		if (!dev_list[i].num)
			continue;

		for (j = 1; j < *dev_list[i].num; j++)
			device_create(sound_class, NULL,
				      MKDEV(SOUND_MAJOR, dev_list[i].minor + (j*0x10)),
				      "%s%d", dev_list[i].name, j);
	}

	if (sound_nblocks >= 1024)
		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++) {
		device_destroy(sound_class, MKDEV(SOUND_MAJOR, dev_list[i].minor));
		if (!dev_list[i].num)
			continue;
		for (j = 1; j < *dev_list[i].num; j++)
			device_destroy(sound_class, MKDEV(SOUND_MAJOR, dev_list[i].minor + (j*0x10)));
	}
	
	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);