via82cxxx_audio.c

iis s3c2410-uda1341语音系统的 开发

static int __init via_ac97_init (struct via_info *card)
{
	int rc;
	u16 tmp16;

	DPRINTK ("ENTER\n");

	assert (card != NULL);

	memset (&card->ac97, 0, sizeof (card->ac97));
	card->ac97.private_data = card;
	card->ac97.codec_read = via_ac97_read_reg;
	card->ac97.codec_write = via_ac97_write_reg;
	card->ac97.codec_wait = via_ac97_codec_wait;

	card->ac97.dev_mixer = register_sound_mixer (&via_mixer_fops, -1);
	if (card->ac97.dev_mixer < 0) {
		printk (KERN_ERR PFX "unable to register AC97 mixer, aborting\n");
		DPRINTK ("EXIT, returning -EIO\n");
		return -EIO;
	}

	rc = via_ac97_reset (card);
	if (rc) {
		printk (KERN_ERR PFX "unable to reset AC97 codec, aborting\n");
		goto err_out;
	}

	if (ac97_probe_codec (&card->ac97) == 0) {
		printk (KERN_ERR PFX "unable to probe AC97 codec, aborting\n");
		rc = -EIO;
		goto err_out;
	}

	/* enable variable rate */
	tmp16 = via_ac97_read_reg (&card->ac97, AC97_EXTENDED_STATUS);
	via_ac97_write_reg (&card->ac97, AC97_EXTENDED_STATUS, tmp16 | 1);

 	/*
 	 * If we cannot enable VRA, we have a locked-rate codec.
 	 * We try again to enable VRA before assuming so, however.
 	 */
 	tmp16 = via_ac97_read_reg (&card->ac97, AC97_EXTENDED_STATUS);
 	if ((tmp16 & 1) == 0) {
 		via_ac97_write_reg (&card->ac97, AC97_EXTENDED_STATUS, tmp16 | 1);
 		tmp16 = via_ac97_read_reg (&card->ac97, AC97_EXTENDED_STATUS);
 		if ((tmp16 & 1) == 0) {
 			card->locked_rate = 1;
 			printk (KERN_WARNING PFX "Codec rate locked at 48Khz\n");
 		}
 	}

	DPRINTK ("EXIT, returning 0\n");
	return 0;

err_out:
	unregister_sound_mixer (card->ac97.dev_mixer);
	DPRINTK ("EXIT, returning %d\n", rc);
	return rc;
}


static void via_ac97_cleanup (struct via_info *card)
{
	DPRINTK ("ENTER\n");

	assert (card != NULL);
	assert (card->ac97.dev_mixer >= 0);

	unregister_sound_mixer (card->ac97.dev_mixer);

	DPRINTK ("EXIT\n");
}



/****************************************************************
 *
 * Interrupt-related code
 *
 */

/**
 *	via_intr_channel - handle an interrupt for a single channel
 *	@chan: handle interrupt for this channel
 *
 *	This is the "meat" of the interrupt handler,
 *	containing the actions taken each time an interrupt
 *	occurs.  All communication and coordination with
 *	userspace takes place here.
 *
 *	Locking: inside card->lock
 */

static void via_intr_channel (struct via_channel *chan)
{
	u8 status;
	int n;

	/* check pertinent bits of status register for action bits */
	status = inb (chan->iobase) & (VIA_SGD_FLAG | VIA_SGD_EOL | VIA_SGD_STOPPED);
	if (!status)
		return;

	/* acknowledge any flagged bits ASAP */
	outb (status, chan->iobase);

	if (!chan->sgtable) /* XXX: temporary solution */
		return;

	/* grab current h/w ptr value */
	n = atomic_read (&chan->hw_ptr);

	/* sanity check: make sure our h/w ptr doesn't have a weird value */
	assert (n >= 0);
	assert (n < chan->frag_number);

	/* reset SGD data structure in memory to reflect a full buffer,
	 * and advance the h/w ptr, wrapping around to zero if needed
	 */
	if (n == (chan->frag_number - 1)) {
		chan->sgtable[n].count = cpu_to_le32(chan->frag_size | VIA_EOL);
		atomic_set (&chan->hw_ptr, 0);
	} else {
		chan->sgtable[n].count = cpu_to_le32(chan->frag_size | VIA_FLAG);
		atomic_inc (&chan->hw_ptr);
	}

	/* accounting crap for SNDCTL_DSP_GETxPTR */
	chan->n_irqs++;
	chan->bytes += chan->frag_size;
	if (chan->bytes < 0) /* handle overflow of 31-bit value */
		chan->bytes = chan->frag_size;

	/* wake up anyone listening to see when interrupts occur */
	if (waitqueue_active (&chan->wait))
		wake_up_all (&chan->wait);

	DPRINTK ("%s intr, status=0x%02X, hwptr=0x%lX, chan->hw_ptr=%d\n",
		 chan->name, status, (long) inl (chan->iobase + 0x04),
		 atomic_read (&chan->hw_ptr));

	/* all following checks only occur when not in mmap(2) mode */
	if (chan->is_mapped)
		return;

	/* If we are recording, then n_frags represents the number
	 * of fragments waiting to be handled by userspace.
	 * If we are playback, then n_frags represents the number
	 * of fragments remaining to be filled by userspace.
	 * We increment here.  If we reach max number of fragments,
	 * this indicates an underrun/overrun.  For this case under OSS,
	 * we stop the record/playback process.
	 */
	if (atomic_read (&chan->n_frags) < chan->frag_number)
		atomic_inc (&chan->n_frags);
	assert (atomic_read (&chan->n_frags) <= chan->frag_number);

	if (atomic_read (&chan->n_frags) == chan->frag_number) {
		chan->is_active = 0;
		via_chan_stop (chan->iobase);
	}

	DPRINTK ("%s intr, channel n_frags == %d\n", chan->name,
		 atomic_read (&chan->n_frags));
}


static void via_interrupt(int irq, void *dev_id, struct pt_regs *regs)
{
	struct via_info *card = dev_id;
	u32 status32;

	/* to minimize interrupt sharing costs, we use the SGD status
	 * shadow register to check the status of all inputs and
	 * outputs with a single 32-bit bus read.  If no interrupt
	 * conditions are flagged, we exit immediately
	 */
	status32 = inl (card->baseaddr + VIA_BASE0_SGD_STATUS_SHADOW);
	if (!(status32 & VIA_INTR_MASK))
        {
#ifdef CONFIG_MIDI_VIA82CXXX
	    	 if (card->midi_devc)
                    	uart401intr(irq, card->midi_devc, regs);
#endif
		return;
    	}
	DPRINTK ("intr, status32 == 0x%08X\n", status32);

	/* synchronize interrupt handling under SMP.  this spinlock
	 * goes away completely on UP
	 */
	spin_lock (&card->lock);

	if (status32 & VIA_INTR_OUT)
		via_intr_channel (&card->ch_out);
	if (status32 & VIA_INTR_IN)
		via_intr_channel (&card->ch_in);
	if (status32 & VIA_INTR_FM)
		via_intr_channel (&card->ch_fm);

	spin_unlock (&card->lock);
}


/**
 *	via_interrupt_init - Initialize interrupt handling
 *	@card: Private info for specified board
 *
 *	Obtain and reserve IRQ for using in handling audio events.
 *	Also, disable any IRQ-generating resources, to make sure
 *	we don't get interrupts before we want them.
 */

static int via_interrupt_init (struct via_info *card)
{
	u8 tmp8;

	DPRINTK ("ENTER\n");

	assert (card != NULL);
	assert (card->pdev != NULL);

	/* check for sane IRQ number. can this ever happen? */
	if (card->pdev->irq < 2) {
		printk (KERN_ERR PFX "insane IRQ %d, aborting\n",
			card->pdev->irq);
		DPRINTK ("EXIT, returning -EIO\n");
		return -EIO;
	}

	/* make sure FM irq is not routed to us */
	pci_read_config_byte (card->pdev, VIA_FM_NMI_CTRL, &tmp8);
	if ((tmp8 & VIA_CR48_FM_TRAP_TO_NMI) == 0) {
		tmp8 |= VIA_CR48_FM_TRAP_TO_NMI;
		pci_write_config_byte (card->pdev, VIA_FM_NMI_CTRL, tmp8);
	}

	if (request_irq (card->pdev->irq, via_interrupt, SA_SHIRQ, VIA_MODULE_NAME, card)) {
		printk (KERN_ERR PFX "unable to obtain IRQ %d, aborting\n",
			card->pdev->irq);
		DPRINTK ("EXIT, returning -EBUSY\n");
		return -EBUSY;
	}

	DPRINTK ("EXIT, returning 0\n");
	return 0;
}


/****************************************************************
 *
 * OSS DSP device
 *
 */

static struct file_operations via_dsp_fops = {
	owner:		THIS_MODULE,
	open:		via_dsp_open,
	release:	via_dsp_release,
	read:		via_dsp_read,
	write:		via_dsp_write,
	poll:		via_dsp_poll,
	llseek: 	no_llseek,
	ioctl:		via_dsp_ioctl,
	mmap:		via_dsp_mmap,
};


static int __init via_dsp_init (struct via_info *card)
{
	u8 tmp8;

	DPRINTK ("ENTER\n");

	assert (card != NULL);

	/* turn off legacy features, if not already */
	pci_read_config_byte (card->pdev, VIA_FUNC_ENABLE, &tmp8);
	if (tmp8 & (VIA_CR42_SB_ENABLE |  VIA_CR42_FM_ENABLE)) {
		tmp8 &= ~(VIA_CR42_SB_ENABLE | VIA_CR42_FM_ENABLE);
		pci_write_config_byte (card->pdev, VIA_FUNC_ENABLE, tmp8);
	}

	via_stop_everything (card);

	card->dev_dsp = register_sound_dsp (&via_dsp_fops, -1);
	if (card->dev_dsp < 0) {
		DPRINTK ("EXIT, returning -ENODEV\n");
		return -ENODEV;
	}
	DPRINTK ("EXIT, returning 0\n");
	return 0;
}


static void via_dsp_cleanup (struct via_info *card)
{
	DPRINTK ("ENTER\n");

	assert (card != NULL);
	assert (card->dev_dsp >= 0);

	via_stop_everything (card);

	unregister_sound_dsp (card->dev_dsp);

	DPRINTK ("EXIT\n");
}


static struct page * via_mm_nopage (struct vm_area_struct * vma,
				    unsigned long address, int write_access)
{
	struct via_info *card = vma->vm_private_data;
	struct via_channel *chan = &card->ch_out;
	struct page *dmapage;
	unsigned long pgoff;
	int rd, wr;

	DPRINTK ("ENTER, start %lXh, ofs %lXh, pgoff %ld, addr %lXh, wr %d\n",
		 vma->vm_start,
		 address - vma->vm_start,
		 (address - vma->vm_start) >> PAGE_SHIFT,
		 address,
		 write_access);

        if (address > vma->vm_end) {
		DPRINTK ("EXIT, returning NOPAGE_SIGBUS\n");
		return NOPAGE_SIGBUS; /* Disallow mremap */
	}
        if (!card) {
		DPRINTK ("EXIT, returning NOPAGE_OOM\n");
		return NOPAGE_OOM;	/* Nothing allocated */
	}

	pgoff = vma->vm_pgoff + ((address - vma->vm_start) >> PAGE_SHIFT);
	rd = card->ch_in.is_mapped;
	wr = card->ch_out.is_mapped;

#ifndef VIA_NDEBUG
	{
	unsigned long max_bufs = chan->frag_number;
	if (rd && wr) max_bufs *= 2;
	/* via_dsp_mmap() should ensure this */
	assert (pgoff < max_bufs);
	}
#endif

	/* if full-duplex (read+write) and we have two sets of bufs,
	 * then the playback buffers come first, sez soundcard.c */
	if (pgoff >= chan->page_number) {
		pgoff -= chan->page_number;
		chan = &card->ch_in;
	} else if (!wr)
		chan = &card->ch_in;

	assert ((((unsigned long)chan->pgtbl[pgoff].cpuaddr) % PAGE_SIZE) == 0);

	dmapage = virt_to_page (chan->pgtbl[pgoff].cpuaddr);
	DPRINTK ("EXIT, returning page %p for cpuaddr %lXh\n",
		 dmapage, (unsigned long) chan->pgtbl[pgoff].cpuaddr);
	get_page (dmapage);
	return dmapage;
}


#ifndef VM_RESERVED
static int via_mm_swapout (struct page *page, struct file *filp)
{
	return 0;
}
#endif /* VM_RESERVED */


struct vm_operations_struct via_mm_ops = {
	nopage:		via_mm_nopage,

#ifndef VM_RESERVED
	swapout:	via_mm_swapout,
#endif
};


static int via_dsp_mmap(struct file *file, struct vm_area_struct *vma)
{
	struct via_info *card;
	int nonblock = (file->f_flags & O_NONBLOCK);
	int rc = -EINVAL, rd=0, wr=0;
	unsigned long max_size, size, start, offset;

	assert (file != NULL);
	assert (vma != NULL);
	card = file->private_data;
	assert (card != NULL);

	DPRINTK ("ENTER, start %lXh, size %ld, pgoff %ld\n",
		 vma->vm_start,
		 vma->vm_end - vma->vm_start,
		 vma->vm_pgoff);

	max_size = 0;
	if (vma->vm_flags & VM_READ) {
		rd = 1;
		via_chan_set_buffering(card, &card->ch_in, -1);
		via_chan_buffer_init (card, &card->ch_in);
		max_size += card->ch_in.page_number << PAGE_SHIFT;
	}
	if (vma->vm_flags & VM_WRITE) {
		wr = 1;
		via_chan_set_buffering(card, &card->ch_out, -1);
		via_chan_buffer_init (card, &card->ch_out);
		max_size += card->ch_out.page_number << PAGE_SHIFT;
	}

	start = vma->vm_start;
	offset = (vma->vm_pgoff << PAGE_SHIFT);
	size = vma->vm_end - vma->vm_start;

	/* some basic size/offset sanity checks */
	if (size > max_size)
		goto out;
	if (offset > max_size - size)
		goto out;

	rc = via_syscall_down (card, nonblock);
	if (rc) goto out;

	vma->vm_ops = &via_mm_ops;
	vma->vm_private_data = card;

#ifdef VM_RESERVED
	vma->vm_flags |= VM_RESERVED;
#endif

	if (rd)
		card->ch_in.is_mapped = 1;
	if (wr)
		card->ch_out.is_mapped = 1;

	up (&card->syscall_sem);
	rc = 0;

out:
	DPRINTK ("EXIT, returning %d\n", rc);
	return rc;
}


static ssize_t via_dsp_do_read (struct via_info *card,
				char *userbuf, size_t count,
				int nonblock)
{
        DECLARE_WAITQUEUE(wait, current);
	const char *orig_userbuf = userbuf;
	struct via_channel *chan = &card->ch_in;
	size_t size;
	int n, tmp;
	ssize_t ret = 0;

	/* if SGD has not yet been started, start it */
	via_chan_maybe_start (chan);

handle_one_block:
	/* just to be a nice neighbor */
	/* Thomas Sailer:
	 * But also to ourselves, release semaphore if we do so */
	if (current->need_resched) {
		up(&card->syscall_sem);
		schedule ();
		ret = via_syscall_down (card, nonblock);
		if (ret)
			goto out;
	}

	/* grab current channel software pointer.  In the case of
	 * recording, this is pointing to the next buffer that
	 * will receive data from the audio hardware.
	 */
	n = chan->sw_ptr;

	/* n_frags represents the number of fragments waiting
	 * to be copied to userland.  sleep until at least
	 * one buffer has been read from the audio hardware.
	 */
	add_wait_queue(&chan->wait, &wait);
	for (;;) {
		__set_current_state(TASK_INTERRUPTIBLE);
		tmp = atomic_read (&chan->n_frags);
		assert (tmp >= 0);
		assert (tmp <= chan->frag_number);
		if (tmp)
			break;
		if (nonblock || !chan->is_active) {
			ret = -EAGAIN;
			break;
		}

		up(&card->syscall_sem);

		DPRINTK ("Sleeping on block %d\n", n);
		schedule();

		ret = via_syscall_down (card, nonblock);
		if (ret)
			break;

		if (signal_pending (current)) {
			ret = -ERESTARTSYS;
			break;