sb_audio.c

基于组件方式开发操作系统的OSKIT源代码

static short sbpro_audio_set_channels(int dev, short channels)
{
	sb_devc *devc = audio_devs[dev]->devc;

	if (channels == 1 || channels == 2)
	{
		if (channels != devc->channels)
		{
			devc->channels = channels;
			if (devc->model == MDL_SBPRO && devc->channels == 2)
				sbpro_audio_set_speed(dev, devc->speed);
		}
	}
	return devc->channels;
}

static int jazz16_audio_set_speed(int dev, int speed)
{
	sb_devc *devc = audio_devs[dev]->devc;

	if (speed > 0)
	{
		int tmp;
		int s = speed * devc->channels;

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

		devc->tconst = (256 - ((1000000 + s / 2) / s)) & 0xff;

		tmp = 256 - devc->tconst;
		speed = ((1000000 + tmp / 2) / tmp) / devc->channels;

		devc->speed = speed;
	}
	return devc->speed;
}

/*
 * SB16 specific routines
 */

static int sb16_audio_set_speed(int dev, int speed)
{
	sb_devc *devc = audio_devs[dev]->devc;
	int	max_speed = devc->submodel == SUBMDL_ALS100 ? 48000 : 44100;

	if (speed > 0)
	{
		if (speed < 5000)	/* which of these */
			speed = 4000;	/* is correct ??? */

		if (speed > max_speed)
			speed = max_speed;

		devc->speed = speed;
	}
	return devc->speed;
}

static unsigned int sb16_audio_set_bits(int dev, unsigned int bits)
{
	sb_devc *devc = audio_devs[dev]->devc;

	if (bits != 0)
	{
		if (bits == AFMT_U8 || bits == AFMT_S16_LE)
			devc->bits = bits;
		else
			devc->bits = AFMT_U8;
	}

	return devc->bits;
}

static int sb16_audio_prepare_for_input(int dev, int bsize, int bcount)
{
	sb_devc *devc = audio_devs[dev]->devc;

	if (!devc->fullduplex)
	{
		audio_devs[dev]->dmap_out->dma =
			audio_devs[dev]->dmap_in->dma =
				devc->bits == AFMT_S16_LE ?
					devc->dma16 : devc->dma8;
	}
	else if (devc->bits == AFMT_S16_LE)
	{
		audio_devs[dev]->dmap_out->dma = devc->dma8;
		audio_devs[dev]->dmap_in->dma = devc->dma16;
	}
	else
	{
		audio_devs[dev]->dmap_out->dma = devc->dma16;
		audio_devs[dev]->dmap_in->dma = devc->dma8;
	}

	devc->trigger_bits = 0;
	return 0;
}

static int sb16_audio_prepare_for_output(int dev, int bsize, int bcount)
{
	sb_devc *devc = audio_devs[dev]->devc;

	if (!devc->fullduplex)
	{
		audio_devs[dev]->dmap_out->dma =
			audio_devs[dev]->dmap_in->dma =
				devc->bits == AFMT_S16_LE ?
					devc->dma16 : devc->dma8;
	}
	else if (devc->bits == AFMT_S16_LE)
	{
		audio_devs[dev]->dmap_out->dma = devc->dma8;
		audio_devs[dev]->dmap_in->dma = devc->dma16;
	}
	else
	{
		audio_devs[dev]->dmap_out->dma = devc->dma16;
		audio_devs[dev]->dmap_in->dma = devc->dma8;
	}

	devc->trigger_bits = 0;
	return 0;
}

static void sb16_audio_output_block(int dev, unsigned long buf, int count,
			int intrflag)
{
	unsigned long   flags, cnt;
	sb_devc        *devc = audio_devs[dev]->devc;
	unsigned long   bits;

	if (!devc->fullduplex || devc->bits == AFMT_S16_LE)
	{
		devc->irq_mode = IMODE_OUTPUT;
		devc->intr_active = 1;
	}
	else
	{
		devc->irq_mode_16 = IMODE_OUTPUT;
		devc->intr_active_16 = 1;
	}

	/* save value */
	save_flags (flags);
	cli ();
	bits = devc->bits;
	if (devc->fullduplex)
		devc->bits = (devc->bits == AFMT_S16_LE) ?
			AFMT_U8 : AFMT_S16_LE;
	restore_flags (flags);

	cnt = count;
	if (devc->bits == AFMT_S16_LE)
		cnt >>= 1;
	cnt--;

	save_flags(flags);
	cli();

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

	sb_dsp_command(devc, 0x41);
	sb_dsp_command(devc, (unsigned char) ((devc->speed >> 8) & 0xff));
	sb_dsp_command(devc, (unsigned char) (devc->speed & 0xff));

	sb_dsp_command(devc, (devc->bits == AFMT_S16_LE ? 0xb6 : 0xc6));
	sb_dsp_command(devc, ((devc->channels == 2 ? 0x20 : 0) +
			      (devc->bits == AFMT_S16_LE ? 0x10 : 0)));
	sb_dsp_command(devc, (unsigned char) (cnt & 0xff));
	sb_dsp_command(devc, (unsigned char) (cnt >> 8));

	/* restore real value after all programming */
	devc->bits = bits;
	restore_flags(flags);
}

static void sb16_audio_start_input(int dev, unsigned long buf, int count, int intrflag)
{
	unsigned long   flags, cnt;
	sb_devc        *devc = audio_devs[dev]->devc;

	if (!devc->fullduplex || devc->bits != AFMT_S16_LE)
	{
		devc->irq_mode = IMODE_INPUT;
		devc->intr_active = 1;
	}
	else
	{
		devc->irq_mode_16 = IMODE_INPUT;
		devc->intr_active_16 = 1;
	}

	cnt = count;
	if (devc->bits == AFMT_S16_LE)
		cnt >>= 1;
	cnt--;

	save_flags(flags);
	cli();

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

	sb_dsp_command(devc, 0x42);
	sb_dsp_command(devc, (unsigned char) ((devc->speed >> 8) & 0xff));
	sb_dsp_command(devc, (unsigned char) (devc->speed & 0xff));

	sb_dsp_command(devc, (devc->bits == AFMT_S16_LE ? 0xbe : 0xce));
	sb_dsp_command(devc, ((devc->channels == 2 ? 0x20 : 0) +
			      (devc->bits == AFMT_S16_LE ? 0x10 : 0)));
	sb_dsp_command(devc, (unsigned char) (cnt & 0xff));
	sb_dsp_command(devc, (unsigned char) (cnt >> 8));

	restore_flags(flags);
}

static void sb16_audio_trigger(int dev, int bits)
{
	sb_devc *devc = audio_devs[dev]->devc;

	int bits_16 = bits & devc->irq_mode_16;
	bits &= devc->irq_mode;

	if (!bits && !bits_16)
		sb_dsp_command(devc, 0xd0);	/* Halt DMA */
	else
	{
		if (bits)
		{
			switch (devc->irq_mode)
			{
				case IMODE_INPUT:
					sb16_audio_start_input(dev,
							devc->trg_buf,
							devc->trg_bytes,
							devc->trg_intrflag);
					break;

				case IMODE_OUTPUT:
					sb16_audio_output_block(dev,
							devc->trg_buf,
							devc->trg_bytes,
							devc->trg_intrflag);
					break;
			}
		}
		if (bits_16)
		{
			switch (devc->irq_mode_16)
			{
				case IMODE_INPUT:
					sb16_audio_start_input(dev,
							devc->trg_buf_16,
							devc->trg_bytes_16,
							devc->trg_intrflag_16);
					break;

				case IMODE_OUTPUT:
					sb16_audio_output_block(dev,
							devc->trg_buf_16,
							devc->trg_bytes_16,
							devc->trg_intrflag_16);
					break;
			}
		}
	}

	devc->trigger_bits = bits | bits_16;
}

static unsigned char lbuf8[2048];
static signed short *lbuf16 = (signed short *)lbuf8;
#define LBUFCOPYSIZE 1024
static void
sb16_copy_from_user(int dev,
		char *localbuf, int localoffs,
		const char *userbuf, int useroffs,
		int max_in, int max_out,
		int *used, int *returned,
		int len)
{
	sb_devc       *devc = audio_devs[dev]->devc;
	int           i, c, p, locallen;
	unsigned char *buf8;
	signed short  *buf16;

	/* if not duplex no conversion */
	if (!devc->fullduplex)
	{
		copy_from_user (localbuf + localoffs, userbuf + useroffs, len);
		*used = len;
		*returned = len;
	}
	else if (devc->bits == AFMT_S16_LE)
	{
		/* 16 -> 8 */
		/* max_in >> 1, max number of samples in ( 16 bits ) */
		/* max_out, max number of samples out ( 8 bits ) */
		/* len, number of samples that will be taken ( 16 bits )*/
		/* c, count of samples remaining in buffer ( 16 bits )*/
		/* p, count of samples already processed ( 16 bits )*/
		len = ( (max_in >> 1) > max_out) ? max_out : (max_in >> 1);
		c = len;
		p = 0;
		buf8 = (unsigned char *)(localbuf + localoffs);
		while (c)
		{
			locallen = (c >= LBUFCOPYSIZE ? LBUFCOPYSIZE : c);
			/* << 1 in order to get 16 bit samples */
			copy_from_user (lbuf16,
					userbuf+useroffs + (p << 1),
					locallen << 1);
			for (i = 0; i < locallen; i++)
			{
				buf8[p+i] = ~((lbuf16[i] >> 8) & 0xff) ^ 0x80;
			}
			c -= locallen; p += locallen;
		}
		/* used = ( samples * 16 bits size ) */
		*used = len << 1;
		/* returned = ( samples * 8 bits size ) */
		*returned = len;
	}
	else
	{
		/* 8 -> 16 */
		/* max_in, max number of samples in ( 8 bits ) */
		/* max_out >> 1, max number of samples out ( 16 bits ) */
		/* len, number of samples that will be taken ( 8 bits )*/
		/* c, count of samples remaining in buffer ( 8 bits )*/
		/* p, count of samples already processed ( 8 bits )*/
		len = max_in > (max_out >> 1) ? (max_out >> 1) : max_in;
		c = len;
		p = 0;
		buf16 = (signed short *)(localbuf + localoffs);
		while (c)
		{
			locallen = (c >= LBUFCOPYSIZE ? LBUFCOPYSIZE : c);
			copy_from_user (lbuf8,
					userbuf+useroffs + p,
					locallen);
			for (i = 0; i < locallen; i++)
			{
				buf16[p+i] = (~lbuf8[i] ^ 0x80) << 8;
			}
	      		c -= locallen; p += locallen;
		}
		/* used = ( samples * 8 bits size ) */
		*used = len;
		/* returned = ( samples * 16 bits size ) */
		*returned = len << 1;
	}
}

static void
sb16_audio_mmap(int dev)
{
	sb_devc       *devc = audio_devs[dev]->devc;
	devc->fullduplex = 0;
}

static struct audio_driver sb1_audio_driver =	/* SB1.x */
{
	sb_audio_open,
	sb_audio_close,
	sb_set_output_parms,
	sb_set_input_parms,
	NULL, /* ioctl */
	sb1_audio_prepare_for_input,
	sb1_audio_prepare_for_output,
	sb1_audio_halt_xfer,
	NULL,			/* local_qlen */
	NULL,			/* copy_from_user */
	NULL,
	NULL,
	sb1_audio_trigger,
	sb1_audio_set_speed,
	sb1_audio_set_bits,
	sb1_audio_set_channels
};

static struct audio_driver sb20_audio_driver =	/* SB2.0 */
{
	sb_audio_open,
	sb_audio_close,
	sb_set_output_parms,
	sb_set_input_parms,
	NULL,
	sb1_audio_prepare_for_input,
	sb1_audio_prepare_for_output,
	sb1_audio_halt_xfer,
	NULL,			/* local_qlen */
	NULL,			/* copy_from_user */
	NULL,
	NULL,
	sb20_audio_trigger,
	sb1_audio_set_speed,
	sb1_audio_set_bits,
	sb1_audio_set_channels
};

static struct audio_driver sb201_audio_driver =		/* SB2.01 */
{
	sb_audio_open,
	sb_audio_close,
	sb_set_output_parms,
	sb_set_input_parms,
	NULL,
	sb1_audio_prepare_for_input,
	sb1_audio_prepare_for_output,
	sb1_audio_halt_xfer,
	NULL,			/* local_qlen */
	NULL,			/* copy_from_user */
	NULL,
	NULL,
	sb20_audio_trigger,
	sb201_audio_set_speed,
	sb1_audio_set_bits,
	sb1_audio_set_channels
};

static struct audio_driver sbpro_audio_driver =		/* SB Pro */
{
	sb_audio_open,
	sb_audio_close,
	sb_set_output_parms,
	sb_set_input_parms,
	NULL,
	sbpro_audio_prepare_for_input,
	sbpro_audio_prepare_for_output,
	sb1_audio_halt_xfer,
	NULL,			/* local_qlen */
	NULL,			/* copy_from_user */
	NULL,
	NULL,
	sb20_audio_trigger,
	sbpro_audio_set_speed,
	sb1_audio_set_bits,
	sbpro_audio_set_channels
};

static struct audio_driver jazz16_audio_driver =	/* Jazz16 and SM Wave */
{
	sb_audio_open,
	sb_audio_close,
	sb_set_output_parms,
	sb_set_input_parms,
	NULL,
	sbpro_audio_prepare_for_input,
	sbpro_audio_prepare_for_output,
	sb1_audio_halt_xfer,
	NULL,			/* local_qlen */
	NULL,			/* copy_from_user */
	NULL,
	NULL,
	sb20_audio_trigger,
	jazz16_audio_set_speed,
	sb16_audio_set_bits,
	sbpro_audio_set_channels
};

static struct audio_driver sb16_audio_driver =	/* SB16 */
{
	sb_audio_open,
	sb_audio_close,
	sb_set_output_parms,
	sb_set_input_parms,
	NULL,
	sb16_audio_prepare_for_input,
	sb16_audio_prepare_for_output,
	sb1_audio_halt_xfer,
	NULL,			/* local_qlen */
	sb16_copy_from_user,	/* copy_from_user */
	NULL,
	NULL,
	sb16_audio_trigger,
	sb16_audio_set_speed,
	sb16_audio_set_bits,
	sbpro_audio_set_channels,
	NULL,
	NULL,
	sb16_audio_mmap
};

void sb_audio_init(sb_devc * devc, char *name)
{
	int audio_flags = 0;
	int format_mask = AFMT_U8;

	struct audio_driver *driver = &sb1_audio_driver;

	switch (devc->model)
	{
		case MDL_SB1:	/* SB1.0 or SB 1.5 */
			DDB(printk("Will use standard SB1.x driver\n"));
			audio_flags = DMA_HARDSTOP;
			break;

		case MDL_SB2:
			DDB(printk("Will use SB2.0 driver\n"));
			audio_flags = DMA_AUTOMODE;
			driver = &sb20_audio_driver;
			break;

		case MDL_SB201:
			DDB(printk("Will use SB2.01 (high speed) driver\n"));
			audio_flags = DMA_AUTOMODE;
			driver = &sb201_audio_driver;
			break;

		case MDL_JAZZ:
		case MDL_SMW:
			DDB(printk("Will use Jazz16 driver\n"));
			audio_flags = DMA_AUTOMODE;
			format_mask |= AFMT_S16_LE;
			driver = &jazz16_audio_driver;
			break;

		case MDL_ESS:
			DDB(printk("Will use ESS ES688/1688 driver\n"));
			driver = ess_audio_init (devc, &audio_flags, &format_mask);
			break;

		case MDL_SB16:
			DDB(printk("Will use SB16 driver\n"));
			audio_flags = DMA_AUTOMODE;
			format_mask |= AFMT_S16_LE;
			if (devc->dma8 != devc->dma16 && devc->dma16 != -1)
			{
				audio_flags |= DMA_DUPLEX;
				devc->duplex = 1;
			}
			driver = &sb16_audio_driver;
			break;

		default:
			DDB(printk("Will use SB Pro driver\n"));
			audio_flags = DMA_AUTOMODE;
			driver = &sbpro_audio_driver;
	}

	if ((devc->dev = sound_install_audiodrv(AUDIO_DRIVER_VERSION,
				name,driver, sizeof(struct audio_driver),
				audio_flags, format_mask, devc,
				devc->dma8,
				devc->duplex ? devc->dma16 : devc->dma8)) < 0)
	{
		  printk(KERN_ERR "Sound Blaster:  unable to install audio.\n");
		  return;
	}
	audio_devs[devc->dev]->mixer_dev = devc->my_mixerdev;
	audio_devs[devc->dev]->min_fragment = 5;
}

#endif