/*
 * 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.
 */
#include <linux/config.h>

#include "sound_config.h"

#if defined(MODULE) || ( defined(CONFIG_PAS) && defined(CONFIG_AUDIO) )

#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 = 0;	/* 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 = 0;	/* filter FLAG */
static unsigned char pcm_mode = PCM_NON;
static unsigned long pcm_count = 0;
static unsigned short pcm_bitsok = 8;	/* mask of OK bits */
static int      pcm_busy = 0;
int             pas_audiodev = 0;
static int      open_mode = 0;

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 = (596590 + (arg / 2)) / arg;
		  arg = (596590 + (foo / 2)) / foo;
	} else
	  {
		  foo = (1193180 + (arg / 2)) / arg;
		  arg = (1193180 + (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

	save_flags(flags);
	cli();

	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);

	restore_flags(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, caddr_t arg)
{
	int             val;

	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:
		  val = *(int *) arg;
		  return (*(int *) arg = pcm_set_speed(val));
		  break;

	  case SOUND_PCM_READ_RATE:
		  return (*(int *) arg = pcm_speed);
		  break;

	  case SNDCTL_DSP_STEREO:
		  val = *(int *) arg;
		  return (*(int *) arg = pcm_set_channels(val + 1) - 1);
		  break;

	  case SOUND_PCM_WRITE_CHANNELS:
		  val = *(int *) arg;
		  return (*(int *) arg = pcm_set_channels(val));
		  break;

	  case SOUND_PCM_READ_CHANNELS:
		  return (*(int *) arg = pcm_channels);
		  break;

	  case SNDCTL_DSP_SETFMT:
		  val = *(int *) arg;
		  return (*(int *) arg = pcm_set_bits(val));
		  break;

	  case SOUND_PCM_READ_BITS:
		  return (*(int *) arg = pcm_bits);

	  default:
		  return -EINVAL;
	  }

	return -EINVAL;
}

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));

	save_flags(flags);
	cli();
	if (pcm_busy)
	  {
		  restore_flags(flags);
		  return -EBUSY;
	  }
	pcm_busy = 1;
	restore_flags(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"));

	save_flags(flags);
	cli();

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

	pcm_busy = 0;
	restore_flags(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;

	save_flags(flags);
	cli();

	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;

	restore_flags(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;

	save_flags(flags);
	cli();

	/* 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;

	restore_flags(flags);
}

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

	save_flags(flags);
	cli();
	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);

	restore_flags(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 =
{
	pas_audio_open,
	pas_audio_close,
	pas_audio_output_block,
	pas_audio_start_input,
	pas_audio_ioctl,
	pas_audio_prepare_for_input,
	pas_audio_prepare_for_output,
	pas_audio_reset,
	NULL,
	NULL,
	NULL,
	NULL,
	pas_audio_trigger
};

void
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_alloc_audiodev()) != -1)
	  {

		  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)
		    {
			    return;
		    }
	} else
		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("PAS: Unexpected PCM interrupt\n");
		    }
	  }
}

#endif
