path: root/sound/oss/audio.c

/*
 * 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)