1. 根目录:
2. sound
3. oss
4. pas2_pcm.c

/*
 * pas2_pcm.c Audio routines for PAS16
 *
 *
 * 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)
 * Alan Cox	   : Swatted a double allocation of device bug. Made a few
 *		     more things module options.
 * Bartlomiej Zolnierkiewicz : Added __init to pas_pcm_init()
 */

#include <linux/init.h>
#include <linux/spinlock.h>
#include <linux/timex.h>
#include "sound_config.h"

#include "pas2.h"

#ifndef DEB
#define DEB(WHAT)
#endif

#define PAS_PCM_INTRBITS (0x08)
/*
 * Sample buffer timer interrupt enable
 */

#define PCM_NON	0
#define PCM_DAC	1
#define PCM_ADC	2

static unsigned long pcm_speed; 	/* sampling rate */
static unsigned char pcm_channels = 1;	/* channels (1 or 2) */
static unsigned char pcm_bits = 8;	/* bits/sample (8 or 16) */
static unsigned char pcm_filter;	/* filter FLAG */
static unsigned char pcm_mode = PCM_NON;
static unsigned long pcm_count;
static unsigned short pcm_bitsok = 8;	/* mask of OK bits */
static int      pcm_busy;
int             pas_audiodev = -1;
static int      open_mode;

extern spinlock_t pas_lock;

static int pcm_set_speed(int arg)
{
	int foo, tmp;
	unsigned long flags;

	if (arg == 0)
		return pcm_speed;

	if (arg > 44100)
		arg = 44100;
	if (arg < 5000)
		arg = 5000;

	if (pcm_channels & 2)
	{
		foo = ((PIT_TICK_RATE / 2) + (arg / 2)) / arg;
		arg = ((PIT_TICK_RATE / 2) + (foo / 2)) / foo;
	}
	else
	{
		foo = (PIT_TICK_RATE + (arg / 2)) / arg;
		arg = (PIT_TICK_RATE + (foo / 2)) / foo;
	}

	pcm_speed = arg;

	tmp = pas_read(0x0B8A);

	/*
	 * Set anti-aliasing filters according to sample rate. You really *NEED*
	 * to enable this feature for all normal recording unless you want to
	 * experiment with aliasing effects.
	 * These filters apply to the selected "recording" source.
	 * I (pfw) don't know the encoding of these 5 bits. The values shown
	 * come from the SDK found on ftp.uwp.edu:/pub/msdos/proaudio/.
	 *
	 * I cleared bit 5 of these values, since that bit controls the master
	 * mute flag. (Olav Wölfelschneider)
	 *
	 */
#if !defined NO_AUTO_FILTER_SET
	tmp &= 0xe0;
	if (pcm_speed >= 2 * 17897)
		tmp |= 0x01;
	else if (pcm_speed >= 2 * 15909)
		tmp |= 0x02;
	else if (pcm_speed >= 2 * 11931)
		tmp |= 0x09;
	else if (pcm_speed >= 2 * 8948)
		tmp |= 0x11;
	else if (pcm_speed >= 2 * 5965)
		tmp |= 0x19;
	else if (pcm_speed >= 2 * 2982)
		tmp |= 0x04;
	pcm_filter = tmp;
#endif

	spin_lock_irqsave(&pas_lock, flags);

	pas_write(tmp & ~(0x40 | 0x80), 0x0B8A);
	pas_write(0x00 | 0x30 | 0x04, 0x138B);
	pas_write(foo & 0xff, 0x1388);
	pas_write((foo >> 8) & 0xff, 0x1388);
	pas_write(tmp, 0x0B8A);

	spin_unlock_irqrestore(&pas_lock, flags);

	return pcm_speed;
}

static int pcm_set_channels(int arg)
{

	if ((arg != 1) && (arg != 2))
		return pcm_channels;

	if (arg != pcm_channels)
	{
		pas_write(pas_read(0xF8A) ^ 0x20, 0xF8A);

		pcm_channels = arg;
		pcm_set_speed(pcm_speed);	/* The speed must be reinitialized */
	}
	return pcm_channels;
}

static int pcm_set_bits(int arg)
{
	if (arg == 0)
		return pcm_bits;

	if ((arg & pcm_bitsok) != arg)
		return pcm_bits;

	if (arg != pcm_bits)
	{
		pas_write(pas_read(0x8389) ^ 0x04, 0x8389);

		pcm_bits = arg;
	}
	return pcm_bits;
}

static int pas_audio_ioctl(int dev, unsigned int cmd, void __user *arg)
{
	int val, ret;
	int __user *p = arg;

	DEB(printk("pas2_pcm.c: static int pas_audio_ioctl(unsigned int cmd = %X, unsigned int arg = %X)\n", cmd, arg));

	switch (cmd) 
	{
	case SOUND_PCM_WRITE_RATE:
		if (get_user(val, p)) 
			return -EFAULT;
		ret = pcm_set_speed(val);
		break;

	case SOUND_PCM_READ_RATE:
		ret = pcm_speed;
		break;
		
	case SNDCTL_DSP_STEREO:
		if (get_user(val, p)) 
			return -EFAULT;
		ret = pcm_set_channels(val + 1) - 1;
		break;

	case SOUND_PCM_WRITE_CHANNELS:
		if (get_user(val, p)) 
			return -EFAULT;
		ret = pcm_set_channels(val);
		break;

	case SOUND_PCM_READ_CHANNELS:
		ret = pcm_channels;
		break;

	case SNDCTL_DSP_SETFMT:
		if (get_user(val, p))
			return -EFAULT;
		ret = pcm_set_bits(val);
		break;
		
	case SOUND_PCM_READ_BITS:
		ret = pcm_bits;
		break;
  
	default:
		return -EINVAL;
	}
	return put_user(ret, p);
}

static void pas_audio_reset(int dev)
{
	DEB(printk("pas2_pcm.c: static void pas_audio_reset(void)\n"));

	pas_write(pas_read(0xF8A) & ~0x40, 0xF8A);	/* Disable PCM */
}

static int pas_audio_open(int dev, int mode)
{
	int             err;
	unsigned long   flags;

	DEB(printk("pas2_pcm.c: static int pas_audio_open(int mode = %X)\n", mode));

	spin_lock_irqsave(&pas_lock, flags);
	if (pcm_busy)
	{
		spin_unlock_irqrestore(&pas_lock, flags);
		return -EBUSY;
	}
	pcm_busy = 1;
	spin_unlock_irqrestore(&pas_lock, flags);

	if ((err = pas_set_intr(PAS_PCM_INTRBITS)) < 0)
		return err;


	pcm_count = 0;
	open_mode = mode;

	return 0;
}

static void pas_audio_close(int dev)
{
	unsigned long   flags;

	DEB(printk("pas2_pcm.c: static void pas_audio_close(void)\n"));

	spin_lock_irqsave(&pas_lock, flags);

	pas_audio_reset(dev);
	pas_remove_intr(PAS_PCM_INTRBITS);
	pcm_mode = PCM_NON;

	pcm_busy = 0;
	spin_unlock_irqrestore(&pas_lock, flags);
}

static void pas_audio_output_block(int dev, unsigned long buf, int count,
		       int intrflag)
{
	unsigned long   flags, cnt;

	DEB(printk("pas2_pcm.c: static void pas_audio_output_block(char *buf = %P, int count = %X)\n", buf, count));

	cnt = count;
	if (audio_devs[dev]->dmap_out->dma > 3)
		cnt >>= 1;

	if (audio_devs[dev]->flags & DMA_AUTOMODE &&
	    intrflag &&
	    cnt == pcm_count)
		return;

	spin_lock_irqsave(&pas_lock, flags);

	pas_write(pas_read(0xF8A) & ~0x40,
		  0xF8A);

	/* DMAbuf_start_dma (dev, buf, count, DMA_MODE_WRITE); */

	if (audio_devs[dev]->dmap_out->dma > 3)
		count >>= 1;

	if (count != pcm_count)
	{
		pas_write(pas_read(0x0B8A) & ~0x80, 0x0B8A);
		pas_write(0x40 | 0x30 | 0x04, 0x138B);
		pas_write(count & 0xff, 0x1389);
		pas_write((count >> 8) & 0xff, 0x1389);
		pas_write(pas_read(0x0B8A) | 0x80, 0x0B8A);

		pcm_count = count;
	}
	pas_write(pas_read(0x0B8A) | 0x80 | 0x40, 0x0B8A);
#ifdef NO_TRIGGER
	pas_write(pas_read(0xF8A) | 0x40 | 0x10, 0xF8A);
#endif

	pcm_mode = PCM_DAC;

	spin_unlock_irqrestore(&pas_lock, flags);
}

static void pas_audio_start_input(int dev, unsigned long buf, int count,
		      int intrflag)
{
	unsigned long   flags;
	int             cnt;

	DEB(printk("pas2_pcm.c: static void pas_audio_start_input(char *buf = %P, int count = %X)\n", buf, count));

	cnt = count;
	if (audio_devs[dev]->dmap_out->dma > 3)
		cnt >>= 1;

	if (audio_devs[pas_audiodev]->flags & DMA_AUTOMODE &&
	    intrflag &&
	    cnt == pcm_count)
		return;

	spin_lock_irqsave(&pas_lock, flags);

	/* DMAbuf_start_dma (dev, buf, count, DMA_MODE_READ); */

	if (audio_devs[dev]->dmap_out->dma > 3)
		count >>= 1;

	if (count != pcm_count)
	{
		pas_write(pas_read(0x0B8A) & ~0x80, 0x0B8A);
		pas_write(0x40 | 0x30 | 0x04, 0x138B);
		pas_write(count & 0xff, 0x1389);
		pas_write((count >> 8) & 0xff, 0x1389);
		pas_write(pas_read(0x0B8A) | 0x80, 0x0B8A);

		pcm_count = count;
	}
	pas_write(pas_read(0x0B8A) | 0x80 | 0x40, 0x0B8A);
#ifdef NO_TRIGGER
	pas_write((pas_read(0xF8A) | 0x40) & ~0x10, 0xF8A);
#endif

	pcm_mode = PCM_ADC;

	spin_unlock_irqrestore(&pas_lock, flags);
}

#ifndef NO_TRIGGER
static void pas_audio_trigger(int dev, int state)
{
	unsigned long   flags;

	spin_lock_irqsave(&pas_lock, flags);
	state &= open_mode;

	if (state & PCM_ENABLE_OUTPUT)
		pas_write(pas_read(0xF8A) | 0x40 | 0x10, 0xF8A);
	else if (state & PCM_ENABLE_INPUT)
		pas_write((pas_read(0xF8A) | 0x40) & ~0x10, 0xF8A);
	else
		pas_write(pas_read(0xF8A) & ~0x40, 0xF8A);

	spin_unlock_irqrestore(&pas_lock, flags);
}
#endif

static int pas_audio_prepare_for_input(int dev, int bsize, int bcount)
{
	pas_audio_reset(dev);
	return 0;
}

static int pas_audio_prepare_for_output(int dev, int bsize, int bcount)
{
	pas_audio_reset(dev);
	return 0;
}

static struct audio_driver pas_audio_driver =
{
	.owner			= THIS_MODULE,
	.open			= pas_audio_open,
	.close			= pas_audio_close,
	.output_block		= pas_audio_output_block,
	.start_input		= pas_audio_start_input,
	.ioctl			= pas_audio_ioctl,
	.prepare_for_input	= pas_audio_prepare_for_input,
	.prepare_for_output	= pas_audio_prepare_for_output,
	.halt_io		= pas_audio_reset,
	.trigger		= pas_audio_trigger
};

void __init pas_pcm_init(struct address_info *hw_config)
{
	DEB(printk("pas2_pcm.c: long pas_pcm_init()\n"));

	pcm_bitsok = 8;
	if (pas_read(0xEF8B) & 0x08)
		pcm_bitsok |= 16;

	pcm_set_speed(DSP_DEFAULT_SPEED);

	if ((pas_audiodev = sound_install_audiodrv(AUDIO_DRIVER_VERSION,
					"Pro Audio Spectrum",
					&pas_audio_driver,
					sizeof(struct audio_driver),
					DMA_AUTOMODE,
					AFMT_U8 | AFMT_S16_LE,
					NULL,
					hw_config->dma,
					hw_config->dma)) < 0)
		printk(KERN_WARNING "PAS16: Too many PCM devices available\n");
}

void pas_pcm_interrupt(unsigned char status, int cause)
{
	if (cause == 1)
	{
		/*
		 * Halt the PCM first. Otherwise we don't have time to start a new
		 * block before the PCM chip proceeds to the next sample
		 */

		if (!(audio_devs[pas_audiodev]->flags & DMA_AUTOMODE))
			pas_write(pas_read(0xF8A) & ~0x40, 0xF8A);

		switch (pcm_mode)
		{
			case PCM_DAC:
				DMAbuf_outputintr(pas_audiodev, 1);
				break;

			case PCM_ADC:
				DMAbuf_inputintr(pas_audiodev);
				break;

			default:
				printk(KERN_WARNING "PAS: Unexpected PCM interrupt\n");
		}
	}
}