NetBSD/sys/dev/isa/ad1848.c

/*	$NetBSD: ad1848.c,v 1.14 1996/12/05 07:01:30 mikel Exp $	*/

/*
 * Copyright (c) 1994 John Brezak
 * Copyright (c) 1991-1993 Regents of the University of California.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the Computer Systems
 *	Engineering Group at Lawrence Berkeley Laboratory.
 * 4. Neither the name of the University nor of the Laboratory may be used
 *    to endorse or promote products derived from this software without
 *    specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 */

/*
 * Copyright by Hannu Savolainen 1994
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met: 1. Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer. 2.
 * Redistributions in binary form must reproduce the above copyright notice,
 * this list of conditions and the following disclaimer in the documentation
 * and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 */
/*
 * Portions of this code are from the VOXware support for the ad1848
 * by Hannu Savolainen <hannu@voxware.pp.fi>
 * 
 * Portions also supplied from the SoundBlaster driver for NetBSD.
 */

/*
 * Todo:
 * - Need datasheet for CS4231 (for use with GUS MAX)
 * - Use fast audio_dma
 */
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/errno.h>
#include <sys/ioctl.h>
#include <sys/syslog.h>
#include <sys/device.h>
#include <sys/proc.h>
#include <sys/buf.h>

#include <machine/cpu.h>
#include <machine/pio.h>

#include <sys/audioio.h>
#include <dev/audio_if.h>

#include <dev/isa/isavar.h>
#include <dev/isa/isadmavar.h>

#include <dev/ic/ad1848reg.h>
#include <dev/ic/cs4231reg.h>
#include <dev/isa/ad1848var.h>
#include <dev/isa/cs4231var.h>

#ifdef AUDIO_DEBUG
extern void Dprintf __P((const char *, ...));
#define DPRINTF(x)	if (ad1848debug) Dprintf x
int	ad1848debug = 0;
#else
#define DPRINTF(x)
#endif

/*
 * Initial values for the indirect registers of CS4248/AD1848.
 */
static int ad1848_init_values[] = {
			/* Left Input Control */
    GAIN_12|INPUT_MIC_GAIN_ENABLE,
			/* Right Input Control */
    GAIN_12|INPUT_MIC_GAIN_ENABLE,
    ATTEN_12,		/* Left Aux #1 Input Control */
    ATTEN_12,		/* Right Aux #1 Input Control */
    ATTEN_12,		/* Left Aux #2 Input Control */
    ATTEN_12,		/* Right Aux #2 Input Control */
    /* bits 5-0 are attenuation select */
    ATTEN_12,		/* Left DAC output Control */
    ATTEN_12,		/* Right DAC output Control */
			/* Clock and Data Format */
    CLOCK_XTAL1|FMT_PCM8,
			/* Interface Config */
    SINGLE_DMA|AUTO_CAL_ENABLE,
    INTERRUPT_ENABLE,	/* Pin control */
    0x00,		/* Test and Init */
    0xca,		/* Misc control */
    ATTEN_0<<2,		/* Digital Mix Control */
    0,			/* Upper base Count */
    0,			/* Lower base Count */

    /* These are for CS4231 &c. only (additional registers): */
    0,			/* Alt feature 1 */
    0,			/* Alt feature 2 */
    ATTEN_12,		/* Left line in */
    ATTEN_12,		/* Right line in */
    0,			/* Timer low */
    0,			/* Timer high */
    0,			/* unused */
    0,			/* unused */
    0,			/* IRQ status */
    0,			/* unused */
			/* Mono input (mic) Control */
    MONO_INPUT_MUTE|ATTEN_6,		/* mute mic by default */
    0,			/* unused */
    0,			/* record format */
    0,			/* upper record count */
    0			/* lower record count */
};

void	ad1848_reset __P((struct ad1848_softc *));
int	ad1848_set_speed __P((struct ad1848_softc *, int));
int	ad1848_set_format __P((struct ad1848_softc *, int, int)); 
void	ad1848_mute_monitor __P((void *, int));

static int ad_read __P((struct ad1848_softc *, int));
static __inline void ad_write __P((struct ad1848_softc *, int, int));
static void ad_set_MCE __P((struct ad1848_softc *, int));
static void wait_for_calibration __P((struct ad1848_softc *));


static int
ad_read(sc, reg)
    struct ad1848_softc *sc;
    int reg;
{
    int x;

    outb(sc->sc_iobase+AD1848_IADDR, (u_char) (reg & 0xff) | sc->MCE_bit);
    x = inb(sc->sc_iobase+AD1848_IDATA);
    /*  printf("(%02x<-%02x) ", reg|sc->MCE_bit, x); */

    return x;
}

static __inline void
ad_write(sc, reg, data)
    struct ad1848_softc *sc;
    int reg;
    int data;
{
    outb(sc->sc_iobase+AD1848_IADDR, (u_char) (reg & 0xff) | sc->MCE_bit);
    outb(sc->sc_iobase+AD1848_IDATA, (u_char) (data & 0xff));
    /* printf("(%02x->%02x) ", reg|sc->MCE_bit, data); */
}

static void
ad_set_MCE(sc, state)
    struct ad1848_softc *sc;
    int state;
{
    if (state)
	sc->MCE_bit = MODE_CHANGE_ENABLE;
    else
	sc->MCE_bit = 0;

    outb(sc->sc_iobase+AD1848_IADDR, sc->MCE_bit);
}

static void
wait_for_calibration(sc)
    struct ad1848_softc *sc;
{
    int timeout = 100000;

    DPRINTF(("ad1848: Auto calibration started.\n"));
    /*
     * Wait until the auto calibration process has finished.
     *
     * 1) Wait until the chip becomes ready (reads don't return 0x80).
     * 2) Wait until the ACI bit of I11 gets on and then off.
     */
    while (timeout > 0 && inb(sc->sc_iobase+AD1848_IADDR) == SP_IN_INIT)
	timeout--;

    if (inb(sc->sc_iobase+AD1848_IADDR) == SP_IN_INIT)
	DPRINTF(("ad1848: Auto calibration timed out(1).\n"));

    outb(sc->sc_iobase+AD1848_IADDR, SP_TEST_AND_INIT);
    timeout = 100000;
    while (timeout > 0 && inb(sc->sc_iobase+AD1848_IADDR) != SP_TEST_AND_INIT)
	timeout--;

    if (inb(sc->sc_iobase+AD1848_IADDR) == SP_TEST_AND_INIT)
	DPRINTF(("ad1848: Auto calibration timed out(1.5).\n"));

    if (!(ad_read(sc, SP_TEST_AND_INIT) & AUTO_CAL_IN_PROG)) {
	timeout = 100000;
	while (timeout > 0 && !(ad_read(sc, SP_TEST_AND_INIT) & AUTO_CAL_IN_PROG))
	    timeout--;

	if (!(ad_read(sc, SP_TEST_AND_INIT) & AUTO_CAL_IN_PROG))
	    DPRINTF(("ad1848: Auto calibration timed out(2).\n"));
    }

    timeout = 100000;
    while (timeout > 0 && ad_read(sc, SP_TEST_AND_INIT) & AUTO_CAL_IN_PROG)
	timeout--;
    if (ad_read(sc, SP_TEST_AND_INIT) & AUTO_CAL_IN_PROG)
        DPRINTF(("ad1848: Auto calibration timed out(3).\n"));
}

#ifdef AUDIO_DEBUG
void ad1848_dump_regs __P((struct ad1848_softc *));

void
ad1848_dump_regs(sc)
    struct ad1848_softc *sc;
{
    int i;
    u_char r;
    
    printf("ad1848 status=%02x", inb(sc->sc_iobase+AD1848_STATUS));
    printf(" regs: ");
    for (i = 0; i < 16; i++) {
	r = ad_read(sc, i);
	printf("%02x ", r);
    }
    if (sc->mode == 2) {
	    for (i = 16; i < 32; i++) {
		    r = ad_read(sc, i);
		    printf("%02x ", r);
	    }
	    printf("\n");
    }
}
#endif

#ifdef NEWCONFIG
void
ad1848_forceintr(sc)
    struct ad1848_softc *sc;
{
    static char dmabuf;

    /*
     * Set up a DMA read of one byte.
     * XXX Note that at this point we haven't called 
     * at_setup_dmachan().  This is okay because it just
     * allocates a buffer in case it needs to make a copy,
     * and it won't need to make a copy for a 1 byte buffer.
     * (I think that calling at_setup_dmachan() should be optional;
     * if you don't call it, it will be called the first time
     * it is needed (and you pay the latency).  Also, you might
     * never need the buffer anyway.)
     */
    isa_dmastart(DMAMODE_READ, &dmabuf, 1, sc->sc_drq);

    ad_write(sc, SP_LOWER_BASE_COUNT, 0);
    ad_write(sc, SP_UPPER_BASE_COUNT, 0);
    ad_write(sc, SP_INTERFACE_CONFIG, PLAYBACK_ENABLE);
}
#endif
    
/*
 * Probe for the ad1848 chip
 */
int
ad1848_probe(sc)
    struct ad1848_softc *sc;
{
    register int iobase = sc->sc_iobase;
    u_char tmp, tmp1 = 0xff, tmp2 = 0xff;
    int i;
    
    if (!AD1848_BASE_VALID(iobase)) {
#ifdef AUDIO_DEBUG
	printf("ad1848: configured iobase %04x invalid\n", iobase);
#endif
	return 0;
    }

    sc->sc_iobase = iobase;

    /* Is there an ad1848 chip ? */
    sc->MCE_bit = MODE_CHANGE_ENABLE;
    sc->mode = 1;	/* MODE 1 = original ad1848/ad1846/cs4248 */
    
    /*
     * Check that the I/O address is in use.
     *
     * The SP_IN_INIT bit of the base I/O port is known to be 0 after the
     * chip has performed its power-on initialization. Just assume
     * this has happened before the OS is starting.
     *
     * If the I/O address is unused, inb() typically returns 0xff.
     */
    if (((tmp = inb(iobase+AD1848_IADDR)) & SP_IN_INIT) != 0x00) { /* Not a AD1848 */
	DPRINTF(("ad_detect_A %x\n", tmp));
	return 0;
    }

    /*
     * Test if it's possible to change contents of the indirect registers.
     * Registers 0 and 1 are ADC volume registers. The bit 0x10 is read only
     * so try to avoid using it.
     */
    ad_write(sc, 0, 0xaa);
    ad_write(sc, 1, 0x45);	/* 0x55 with bit 0x10 clear */

    if ((tmp1 = ad_read(sc, 0)) != 0xaa ||
	(tmp2 = ad_read(sc, 1)) != 0x45) {
	DPRINTF(("ad_detect_B (%x/%x)\n", tmp1, tmp2));
	return 0;
    }

    ad_write(sc, 0, 0x45);
    ad_write(sc, 1, 0xaa);

    if ((tmp1 = ad_read(sc, 0)) != 0x45 ||
	(tmp2 = ad_read(sc, 1)) != 0xaa) {
	DPRINTF(("ad_detect_C (%x/%x)\n", tmp1, tmp2));
	return 0;
    }

    /*
     * The indirect register I12 has some read only bits. Lets
     * try to change them.
     */
    tmp = ad_read(sc, SP_MISC_INFO);
    ad_write(sc, SP_MISC_INFO, (~tmp) & 0x0f);

    if ((tmp & 0x0f) != ((tmp1 = ad_read(sc, SP_MISC_INFO)) & 0x0f)) {
	DPRINTF(("ad_detect_D (%x)\n", tmp1));
	return 0;
    }

    /*
     * MSB and 4 LSBs of the reg I12 tell the chip revision.
     *
     * A preliminary version of the AD1846 data sheet stated that it
     * used an ID field of 0x0B.  The current version, however,
     * states that the AD1846 uses ID 0x0A, just like the AD1848K.
     *
     * this switch statement will need updating as newer clones arrive....
     */
    switch (tmp1 & 0x8f) {
    case 0x09:
	sc->chip_name = "AD1848J";
	break;
    case 0x0A:
	sc->chip_name = "AD1848K";
	break;
#if 0	/* See above */
    case 0x0B:
	sc->chip_name = "AD1846";
	break;
#endif
    case 0x81:
	sc->chip_name = "CS4248revB"; /* or CS4231 rev B; see below */
	break;
    case 0x89:
	sc->chip_name = "CS4248";
	break;
    case 0x8A:
	sc->chip_name = "broken"; /* CS4231/AD1845; see below */
	break;
    default:
	sc->chip_name = "unknown";
	DPRINTF(("ad1848: unknown codec version %#02X\n", (tmp1 & 0x8f)));
    }	
    
    /*
     * The original AD1848/CS4248 has just 16 indirect registers. This means
     * that I0 and I16 should return the same value (etc.).
     * Ensure that the Mode2 enable bit of I12 is 0. Otherwise this test fails
     * with CS4231, AD1845, etc.
     */
    ad_write(sc, SP_MISC_INFO, 0);	/* Mode2 = disabled */

    for (i = 0; i < 16; i++)
	if ((tmp1 = ad_read(sc, i)) != (tmp2 = ad_read(sc, i + 16))) {
	    DPRINTF(("ad_detect_F(%d/%x/%x)\n", i, tmp1, tmp2));
	    return 0;
	}

    /*
     * Try to switch the chip to mode2 (CS4231) by setting the MODE2 bit
     * The bit 0x80 is always 1 in CS4248, CS4231, and AD1845.
     */
    ad_write(sc, SP_MISC_INFO, MODE2);	/* Set mode2, clear 0x80 */

    tmp1 = ad_read(sc, SP_MISC_INFO);
    if ((tmp1 & 0xc0) == (0x80 | MODE2)) {
	/*
	 *      CS4231 or AD1845 detected - is it?
	 *
	 *	Verify that setting I2 doesn't change I18.
	 */
	ad_write(sc, 18, 0x88); /* Set I18 to known value */

	ad_write(sc, 2, 0x45);
	if ((tmp2 = ad_read(sc, 18)) != 0x45) { /* No change -> CS4231? */
	    ad_write(sc, 2, 0xaa);
	    if ((tmp2 = ad_read(sc, 18)) == 0xaa) {     /* Rotten bits? */
		DPRINTF(("ad_detect_H(%x)\n", tmp2));
		return 0;
	    }

	    /*
	     *  It's a CS4231, or another clone with 32 registers.
	     *  Let's find out which by checking I25.
	     */
	    if ((tmp1 & 0x8f) == 0x8a) {
		tmp1 = ad_read(sc, CS_VERSION_ID);
		switch (tmp1 & 0xe7) {
       		case 0xA0:
		    sc->chip_name = "CS4231A";
		    break;
       		case 0x80:
		    /*  XXX I25 no good, AD1845 same as CS4231 */
		    sc->chip_name = "CS4231 or AD1845";
		    break;
       		case 0x82:
		    sc->chip_name = "CS4232";
		    break;
		}
	    }
	    sc->mode = 2;
	}
    }

    /* Wait for 1848 to init */
    while(inb(sc->sc_iobase+AD1848_IADDR) & SP_IN_INIT);
	
    /* Wait for 1848 to autocal */
    outb(sc->sc_iobase+AD1848_IADDR, SP_TEST_AND_INIT);
    while(inb(sc->sc_iobase+AD1848_IDATA) & AUTO_CAL_IN_PROG);

    return 1;
}

/*
 * Attach hardware to driver, attach hardware driver to audio
 * pseudo-device driver .
 */
void
ad1848_attach(sc)
    struct ad1848_softc *sc;
{
    int i;
    struct ad1848_volume vol_mid = {150, 150};
    struct ad1848_volume vol_0   = {0, 0};
    
    sc->sc_locked = 0;

    /* Initialize the ad1848... */
    for (i = 0; i < 16; i++)
	ad_write(sc, i, ad1848_init_values[i]);
    /* ...and additional CS4231 stuff too */
    if (sc->mode == 2) {
#if 0
	    ad_write(sc, SP_INTERFACE_CONFIG, 0); /* disable SINGLE_DMA feature */
#else
	    /* XXX SINGLE_DMA is cleared in ad1848_reset(), due to #if 0 */
#endif
	    for (i = 0x10; i <= 0x1F; i++)
		    if (ad1848_init_values[i] != 0)
			    ad_write(sc, i, ad1848_init_values[i]);
    }
    ad1848_reset(sc);

    /* Set default encoding (ULAW) */
    sc->sc_irate = sc->sc_orate = 8000;
    sc->precision = 8;
    sc->channels = 1;
    sc->encoding = AUDIO_ENCODING_ULAW;
    (void) ad1848_set_in_sr(sc, sc->sc_irate);
    (void) ad1848_set_out_sr(sc, sc->sc_orate);

    /* Set default gains */
    (void) ad1848_set_rec_gain(sc, &vol_mid);
    (void) ad1848_set_out_gain(sc, &vol_mid);
    (void) ad1848_set_mon_gain(sc, &vol_0);
    (void) ad1848_set_aux1_gain(sc, &vol_mid);	/* CD volume */
    if (sc->mode == 2) {
	/* aux1 was really the DAC output */
	(void) ad1848_set_aux2_gain(sc, &vol_mid); /* CD volume */
	(void) cs4231_set_linein_gain(sc, &vol_mid);
	(void) cs4231_set_mono_gain(sc, &vol_0); /* mic */
    } else
	(void) ad1848_set_aux2_gain(sc, &vol_0);

    /* Set default port */
    (void) ad1848_set_rec_port(sc, MIC_IN_PORT);

    printf(": %s", sc->chip_name);
}

/*
 * Various routines to interface to higher level audio driver
 */
int
ad1848_set_rec_gain(sc, gp)
    register struct ad1848_softc *sc;
    struct ad1848_volume *gp;
{
    register u_char reg, gain;
    
    DPRINTF(("ad1848_set_rec_gain: %d:%d\n", gp->left, gp->right));

    sc->rec_gain = *gp;

    gain = (gp->left * GAIN_22_5)/AUDIO_MAX_GAIN;
    reg = ad_read(sc, SP_LEFT_INPUT_CONTROL);
    reg &= INPUT_GAIN_MASK;
    ad_write(sc, SP_LEFT_INPUT_CONTROL, (gain&0x0f)|reg);

    gain = (gp->right * GAIN_22_5)/AUDIO_MAX_GAIN;
    reg = ad_read(sc, SP_RIGHT_INPUT_CONTROL);
    reg &= INPUT_GAIN_MASK;
    ad_write(sc, SP_RIGHT_INPUT_CONTROL, (gain&0x0f)|reg);

    return(0);
}

int
ad1848_get_rec_gain(sc, gp)
    register struct ad1848_softc *sc;
    struct ad1848_volume *gp;
{
    *gp = sc->rec_gain;
    return(0);
}

int
ad1848_set_out_gain(sc, gp)
    register struct ad1848_softc *sc;
    struct ad1848_volume *gp;
{
    u_char reg;
    u_int atten;
    
    DPRINTF(("ad1848_set_out_gain: %d:%d\n", gp->left, gp->right));

    sc->out_gain = *gp;

    atten = ((AUDIO_MAX_GAIN - gp->left) * OUTPUT_ATTEN_BITS)/AUDIO_MAX_GAIN;
    reg = ad_read(sc, SP_LEFT_OUTPUT_CONTROL);
    reg &= OUTPUT_ATTEN_MASK;
    ad_write(sc, SP_LEFT_OUTPUT_CONTROL, (atten&0x3f)|reg);

    atten = ((AUDIO_MAX_GAIN - gp->right) * OUTPUT_ATTEN_BITS)/AUDIO_MAX_GAIN;
    reg = ad_read(sc, SP_RIGHT_OUTPUT_CONTROL);
    reg &= OUTPUT_ATTEN_MASK;
    ad_write(sc, SP_RIGHT_OUTPUT_CONTROL, (atten&0x3f)|reg);

    return(0);
}

int
ad1848_get_out_gain(sc, gp)
    register struct ad1848_softc *sc;
    struct ad1848_volume *gp;
{
    *gp = sc->out_gain;
    return(0);
}

int
ad1848_set_mon_gain(sc, gp)		/* monitor gain */
    register struct ad1848_softc *sc;
    struct ad1848_volume *gp;
{
    u_char reg;
    u_int atten;
    
    DPRINTF(("ad1848_set_mon_gain: %d\n", gp->left));

    sc->mon_gain = *gp;

    atten = ((AUDIO_MAX_GAIN - gp->left) * OUTPUT_ATTEN_BITS)/AUDIO_MAX_GAIN;
    reg = ad_read(sc, SP_DIGITAL_MIX);
    reg &= MIX_ATTEN_MASK;
    ad_write(sc, SP_DIGITAL_MIX, (atten&OUTPUT_ATTEN_BITS)|reg);
    return(0);
}

int
ad1848_get_mon_gain(sc, gp)
    register struct ad1848_softc *sc;
    struct ad1848_volume *gp;
{
    *gp = sc->mon_gain;
    return(0);
}

int
cs4231_set_mono_gain(sc, gp)
    register struct ad1848_softc *sc;
    struct ad1848_volume *gp;
{
    u_char reg, oreg;
    u_int atten;
    
    DPRINTF(("cs4231_set_mono_gain: %d\n", gp->left));

    sc->mono_gain = *gp;

    atten = ((AUDIO_MAX_GAIN - gp->left) * MONO_INPUT_ATTEN_BITS)/AUDIO_MAX_GAIN;
    oreg = reg = ad_read(sc, CS_MONO_IO_CONTROL);
    reg &= MONO_INPUT_ATTEN_MASK;
    ad_write(sc, CS_MONO_IO_CONTROL, (atten&MONO_INPUT_ATTEN_BITS)|reg);
    DPRINTF(("cs4231_set_mono_gain: was:%x\n", oreg));
    return(0);
}

int
cs4231_get_mono_gain(sc, gp)
    register struct ad1848_softc *sc;
    struct ad1848_volume *gp;
{
    *gp = sc->mono_gain;
    return(0);
}

int
ad1848_set_mic_gain(sc, gp)
    register struct ad1848_softc *sc;
    struct ad1848_volume *gp;
{
    u_char reg;
    
    DPRINTF(("cs4231_set_mic_gain: %d\n", gp->left));

    if (gp->left > AUDIO_MAX_GAIN/2) {
	    sc->mic_gain_on = 1;
	    reg = ad_read(sc, SP_LEFT_INPUT_CONTROL);
	    ad_write(sc, SP_LEFT_INPUT_CONTROL, reg | INPUT_MIC_GAIN_ENABLE);
    } else {
	    sc->mic_gain_on = 0;
	    reg = ad_read(sc, SP_LEFT_INPUT_CONTROL);
	    ad_write(sc, SP_LEFT_INPUT_CONTROL, reg & ~INPUT_MIC_GAIN_ENABLE);
    }

    return(0);
}

int
ad1848_get_mic_gain(sc, gp)
    register struct ad1848_softc *sc;
    struct ad1848_volume *gp;
{
	if (sc->mic_gain_on)
		gp->left = gp->right = AUDIO_MAX_GAIN;
	else
		gp->left = gp->right = AUDIO_MIN_GAIN;
	return(0);
}

void
ad1848_mute_monitor(addr, mute)
	void *addr;
	int mute;
{
	register struct ad1848_softc *sc = addr;

	DPRINTF(("ad1848_mute_monitor: %smuting\n", mute ? "" : "un"));
	if (sc->mode == 2) {
		cs4231_mute_monitor(sc, mute);
		cs4231_mute_mono(sc, mute);
		cs4231_mute_line(sc, mute);
	}
		
	ad1848_mute_aux1(sc, mute);
	ad1848_mute_aux2(sc, mute);
}

void
cs4231_mute_monitor(sc, mute)
	register struct ad1848_softc *sc;
	int mute;
{
	u_char reg;
	if (mute) {
		DPRINTF(("cs4231_mute_monitor: muting\n"));
		reg = ad_read(sc, SP_LEFT_OUTPUT_CONTROL);
		ad_write(sc, SP_LEFT_OUTPUT_CONTROL, OUTPUT_MUTE|reg);
		reg = ad_read(sc, SP_RIGHT_OUTPUT_CONTROL);
		ad_write(sc, SP_RIGHT_OUTPUT_CONTROL, OUTPUT_MUTE|reg);
	} else if (!sc->mon_mute) {
		DPRINTF(("cs4231_mute_monitor: unmuting\n"));
		reg = ad_read(sc, SP_LEFT_OUTPUT_CONTROL);
		ad_write(sc, SP_LEFT_OUTPUT_CONTROL, reg & ~OUTPUT_MUTE);
		reg = ad_read(sc, SP_RIGHT_OUTPUT_CONTROL);
		ad_write(sc, SP_RIGHT_OUTPUT_CONTROL, reg & ~OUTPUT_MUTE);
	}
}

void
cs4231_mute_mono(sc, mute)
    register struct ad1848_softc *sc;
    int mute;
{
	u_char reg;
	if (mute) {
		DPRINTF(("cs4231_mute_mono: muting\n"));
		reg = ad_read(sc, CS_MONO_IO_CONTROL);
		ad_write(sc, CS_MONO_IO_CONTROL, MONO_INPUT_MUTE|reg);
	} else if (!sc->mono_mute) {
		DPRINTF(("cs4231_mute_mono: unmuting\n"));
		reg = ad_read(sc, CS_MONO_IO_CONTROL);
		ad_write(sc, CS_MONO_IO_CONTROL, reg & ~MONO_INPUT_MUTE);
	}
}

void
cs4231_mute_line(sc, mute)
    register struct ad1848_softc *sc;
    int mute;
{
	u_char reg;
	if (mute) {
		DPRINTF(("cs4231_mute_line: muting\n"));
		reg = ad_read(sc, CS_LEFT_LINE_CONTROL);
		ad_write(sc, CS_LEFT_LINE_CONTROL, LINE_INPUT_MUTE|reg);
		reg = ad_read(sc, CS_RIGHT_LINE_CONTROL);
		ad_write(sc, CS_RIGHT_LINE_CONTROL, LINE_INPUT_MUTE|reg);
	} else if (!sc->line_mute) {
		DPRINTF(("cs4231_mute_line: unmuting\n"));
		reg = ad_read(sc, CS_LEFT_LINE_CONTROL);
		ad_write(sc, CS_LEFT_LINE_CONTROL, reg & ~LINE_INPUT_MUTE);
		reg = ad_read(sc, CS_RIGHT_LINE_CONTROL);
		ad_write(sc, CS_RIGHT_LINE_CONTROL, reg & ~LINE_INPUT_MUTE);
	}
}

void
ad1848_mute_aux1(sc, mute)
    register struct ad1848_softc *sc;
    int mute;
{
	u_char reg;
	if (mute) {
		DPRINTF(("ad1848_mute_aux1: muting\n"));
		reg = ad_read(sc, SP_LEFT_AUX1_CONTROL);
		ad_write(sc, SP_LEFT_AUX1_CONTROL, AUX_INPUT_MUTE|reg);
		reg = ad_read(sc, SP_RIGHT_AUX1_CONTROL);
		ad_write(sc, SP_RIGHT_AUX1_CONTROL, AUX_INPUT_MUTE|reg);
	} else if (!sc->aux1_mute) {
		DPRINTF(("ad1848_mute_aux1: unmuting\n"));
		reg = ad_read(sc, SP_LEFT_AUX1_CONTROL);
		ad_write(sc, SP_LEFT_AUX1_CONTROL, reg & ~AUX_INPUT_MUTE);
		reg = ad_read(sc, SP_RIGHT_AUX1_CONTROL);
		ad_write(sc, SP_RIGHT_AUX1_CONTROL, reg & ~AUX_INPUT_MUTE);
	}
}

void
ad1848_mute_aux2(sc, mute)
    register struct ad1848_softc *sc;
    int mute;
{
	u_char reg;
	if (mute) {
		DPRINTF(("ad1848_mute_aux2: muting\n"));
		reg = ad_read(sc, SP_LEFT_AUX2_CONTROL);
		ad_write(sc, SP_LEFT_AUX2_CONTROL, AUX_INPUT_MUTE|reg);
		reg = ad_read(sc, SP_RIGHT_AUX2_CONTROL);
		ad_write(sc, SP_RIGHT_AUX2_CONTROL, AUX_INPUT_MUTE|reg);
	} else if (!sc->aux2_mute) {
		DPRINTF(("ad1848_mute_aux2: unmuting\n"));
		reg = ad_read(sc, SP_LEFT_AUX2_CONTROL);
		ad_write(sc, SP_LEFT_AUX2_CONTROL, reg & ~AUX_INPUT_MUTE);
		reg = ad_read(sc, SP_RIGHT_AUX2_CONTROL);
		ad_write(sc, SP_RIGHT_AUX2_CONTROL, reg & ~AUX_INPUT_MUTE);
	}
}

int
ad1848_set_aux1_gain(sc, gp)
    register struct ad1848_softc *sc;
    struct ad1848_volume *gp;
{
    u_char reg;
    u_int atten;
    
    DPRINTF(("ad1848_set_aux1_gain: %d:%d\n", gp->left, gp->right));
	
    sc->aux1_gain = *gp;

    atten = ((AUDIO_MAX_GAIN - gp->left) * AUX_INPUT_ATTEN_BITS)/AUDIO_MAX_GAIN;
    reg = ad_read(sc, SP_LEFT_AUX1_CONTROL);
    reg &= ~(AUX_INPUT_ATTEN_BITS);
    ad_write(sc, SP_LEFT_AUX1_CONTROL, (atten&0x1f)|reg);

    atten = ((AUDIO_MAX_GAIN - gp->right) * AUX_INPUT_ATTEN_BITS)/AUDIO_MAX_GAIN;
    reg = ad_read(sc, SP_RIGHT_AUX1_CONTROL);
    reg &= ~(AUX_INPUT_ATTEN_BITS);
    ad_write(sc, SP_RIGHT_AUX1_CONTROL, (atten&0x1f)|reg);

    return(0);
}

int
ad1848_get_aux1_gain(sc, gp)
    register struct ad1848_softc *sc;
    struct ad1848_volume *gp;
{
    *gp = sc->aux1_gain;
    return(0);
}

int
cs4231_set_linein_gain(sc, gp)
    register struct ad1848_softc *sc;
    struct ad1848_volume *gp;
{
    u_char reg, oregl, oregr;
    u_int atten;
    
    DPRINTF(("ad1848_set_linein_gain: %d:%d\n", gp->left, gp->right));
	
    sc->line_gain = *gp;

    atten = ((AUDIO_MAX_GAIN - gp->left) * LINE_INPUT_ATTEN_BITS)/AUDIO_MAX_GAIN;
    oregl = reg = ad_read(sc, CS_LEFT_LINE_CONTROL);
    reg &= ~(LINE_INPUT_ATTEN_BITS);
    ad_write(sc, CS_LEFT_LINE_CONTROL, (atten&LINE_INPUT_ATTEN_BITS)|reg);

    atten = ((AUDIO_MAX_GAIN - gp->right) * LINE_INPUT_ATTEN_BITS)/AUDIO_MAX_GAIN;
    oregr = reg = ad_read(sc, CS_RIGHT_LINE_CONTROL);
    reg &= ~(LINE_INPUT_ATTEN_BITS);
    ad_write(sc, CS_RIGHT_LINE_CONTROL, (atten&LINE_INPUT_ATTEN_BITS)|reg);

    DPRINTF(("ad1848_set_linein_gain: was %x:%x\n", oregl, oregr));
    return(0);
}

int
cs4231_get_linein_gain(sc, gp)
    register struct ad1848_softc *sc;
    struct ad1848_volume *gp;
{
    *gp = sc->line_gain;
    return(0);
}

int
ad1848_set_aux2_gain(sc, gp)
    register struct ad1848_softc *sc;
    struct ad1848_volume *gp;
{
    u_char reg;
    u_int atten;
    
    DPRINTF(("ad1848_set_aux2_gain: %d:%d\n", gp->left, gp->right));
	
    sc->aux2_gain = *gp;

    atten = ((AUDIO_MAX_GAIN - gp->left) * AUX_INPUT_ATTEN_BITS)/AUDIO_MAX_GAIN;
    reg = ad_read(sc, SP_LEFT_AUX2_CONTROL);
    reg &= ~(AUX_INPUT_ATTEN_BITS);
    ad_write(sc, SP_LEFT_AUX2_CONTROL, (atten&0x1f)|reg);

    atten = ((AUDIO_MAX_GAIN - gp->right) * AUX_INPUT_ATTEN_BITS)/AUDIO_MAX_GAIN;
    reg = ad_read(sc, SP_RIGHT_AUX2_CONTROL);
    reg &= ~(AUX_INPUT_ATTEN_BITS);
    ad_write(sc, SP_RIGHT_AUX2_CONTROL, (atten&0x1f)|reg);

    return(0);
}

int
ad1848_get_aux2_gain(sc, gp)
    register struct ad1848_softc *sc;
    struct ad1848_volume *gp;
{
    *gp = sc->aux2_gain;
    return 0;
}

int
ad1848_set_in_sr(addr, sr)
    void *addr;
    u_long sr;
{
    register struct ad1848_softc *sc = addr;

    DPRINTF(("ad1848_set_in_sr: %d\n", sr));

    sc->sc_irate = sc->sc_orate = ad1848_set_speed(sc, sr);

    return(0);
}

u_long
ad1848_get_in_sr(addr)
    void *addr;
{
    register struct ad1848_softc *sc = addr;

    return(sc->sc_irate);
}

int
ad1848_set_out_sr(addr, sr)
    void *addr;
    u_long sr;
{
    register struct ad1848_softc *sc = addr;

    DPRINTF(("ad1848_set_out_sr: %d\n", sr));

    sc->sc_irate = sc->sc_orate = ad1848_set_speed(sc, sr);

    return(0);
}

u_long
ad1848_get_out_sr(addr)
    void *addr;
{
    register struct ad1848_softc *sc = addr;

    return(sc->sc_orate);
}

int
ad1848_query_encoding(addr, fp)
    void *addr;
    struct audio_encoding *fp;
{
    switch (fp->index) {
    case 0:
	strcpy(fp->name, AudioEmulaw);
	fp->format_id = AUDIO_ENCODING_ULAW;
	break;
    case 1:
	strcpy(fp->name, AudioEalaw);
	fp->format_id = AUDIO_ENCODING_ALAW;
	break;
    case 2:
	strcpy(fp->name, AudioEpcm16);
	fp->format_id = AUDIO_ENCODING_PCM16;
	break;
    case 3:
	strcpy(fp->name, AudioEpcm8);
	fp->format_id = AUDIO_ENCODING_PCM8;
	break;
    default:
	return(EINVAL);
	/*NOTREACHED*/
    }
    return (0);
}

int
ad1848_set_encoding(addr, enc)
    void *addr;
    u_int enc;
{
    register struct ad1848_softc *sc = addr;
	
    DPRINTF(("ad1848_set_encoding: %d\n", enc));

    if (sc->encoding != AUDIO_ENCODING_PCM8 &&
	sc->encoding != AUDIO_ENCODING_PCM16 &&
	sc->encoding != AUDIO_ENCODING_ALAW &&
	sc->encoding != AUDIO_ENCODING_ULAW) {

	sc->encoding = AUDIO_ENCODING_PCM8;
	return (EINVAL);
    }

    sc->encoding = ad1848_set_format(sc, enc, sc->precision);

    if (sc->encoding == -1) {
	sc->encoding = AUDIO_ENCODING_PCM8;
	return (EINVAL);
    }

    return (0);
}

int
ad1848_get_encoding(addr)
    void *addr;
{
    register struct ad1848_softc *sc = addr;

    return(sc->encoding);
}

int
ad1848_set_precision(addr, prec)
    void *addr;
    u_int prec;
{
    register struct ad1848_softc *sc = addr;
	
    DPRINTF(("ad1848_set_precision: %d\n", prec));

    sc->encoding = ad1848_set_format(sc, sc->encoding, prec);
    if (sc->encoding == -1) {
	sc->encoding = AUDIO_ENCODING_PCM16;
	sc->precision = 16;
	return (EINVAL);
    }
    sc->precision = prec;
	
    return (0);
}

int
ad1848_get_precision(addr)
    void *addr;
{
    register struct ad1848_softc *sc = addr;

    return(sc->precision);
}

int
ad1848_set_channels(addr, chans)
    void *addr;
    int chans;
{
    register struct ad1848_softc *sc = addr;
	
    DPRINTF(("ad1848_set_channels: %d\n", chans));

    if (chans < 1 || chans > 2)
	return(EINVAL);

    sc->channels = chans;

    return(0);
}

int
ad1848_get_channels(addr)
    void *addr;
{
    register struct ad1848_softc *sc = addr;

    return(sc->channels);
}

int
ad1848_set_rec_port(sc, port)
    register struct ad1848_softc *sc;
    int port;
{
    u_char inp, reg;
    
    DPRINTF(("ad1848_set_rec_port: 0x%x\n", port));

    if (port == MIC_IN_PORT) {
	inp = MIC_INPUT;
    }
    else if (port == LINE_IN_PORT) {
	inp = LINE_INPUT;
    }
    else if (port == DAC_IN_PORT) {
	inp = MIXED_DAC_INPUT;
    }
    else if (sc->mode == 2 && port == AUX1_IN_PORT) {
	inp = AUX_INPUT;
    }
    else
	return(EINVAL);

    reg = ad_read(sc, SP_LEFT_INPUT_CONTROL);
    reg &= INPUT_SOURCE_MASK;
    ad_write(sc, SP_LEFT_INPUT_CONTROL, (inp|reg));

    reg = ad_read(sc, SP_RIGHT_INPUT_CONTROL);
    reg &= INPUT_SOURCE_MASK;
    ad_write(sc, SP_RIGHT_INPUT_CONTROL, (inp|reg));

    sc->rec_port = port;

    return(0);
}

int
ad1848_get_rec_port(sc)
    register struct ad1848_softc *sc;
{
    return(sc->rec_port);
}

int
ad1848_round_blocksize(addr, blk)
    void *addr;
    int blk;
{
    register struct ad1848_softc *sc = addr;

    sc->sc_lastcc = -1;

    /* Higher speeds need bigger blocks to avoid popping and silence gaps. */
    if ((sc->sc_orate > 8000 || sc->sc_irate > 8000) && blk < NBPG/2)
	    blk = NBPG/2;
    /* don't try to DMA too much at once, though. */
    if (blk > NBPG)
	blk = NBPG;

    if (sc->channels == 2)
	return (blk & ~1); /* must be even to preserve stereo separation */
    else
	return(blk);	/* Anything goes :-) */
}

u_int
ad1848_get_silence(enc)
    int enc;
{
#define ULAW_SILENCE	0x7f
#define ALAW_SILENCE	0x55
#define LINEAR_SILENCE	0
    u_int auzero;
    
    switch (enc) {
    case AUDIO_ENCODING_ULAW:
	auzero = ULAW_SILENCE; 
	break;
    case AUDIO_ENCODING_ALAW:
	auzero = ALAW_SILENCE;
	break;
    case AUDIO_ENCODING_PCM8:
    case AUDIO_ENCODING_PCM16:
    default:
	auzero = LINEAR_SILENCE;
	break;
    }

    return(auzero);
}


int
ad1848_open(sc, dev, flags)
    struct ad1848_softc *sc;
    dev_t dev;
    int flags;
{
    DPRINTF(("ad1848_open: sc=0x%x\n", sc));

    sc->sc_intr = 0;
    sc->sc_lastcc = -1;
    sc->sc_locked = 0;

    /* Enable interrupts */
    DPRINTF(("ad1848_open: enable intrs\n"));
    ad_write(sc, SP_PIN_CONTROL, INTERRUPT_ENABLE|ad_read(sc, SP_PIN_CONTROL));

#ifdef AUDIO_DEBUG
    if (ad1848debug)
	ad1848_dump_regs(sc);
#endif

    return 0;
}

/*
 * Close function is called at splaudio().
 */
void
ad1848_close(addr)
    void *addr;
{
    struct ad1848_softc *sc = addr;
    register u_char r;
    
    sc->sc_intr = 0;

    DPRINTF(("ad1848_close: stop DMA\n"));
    ad_write(sc, SP_LOWER_BASE_COUNT, (u_char)0);
    ad_write(sc, SP_UPPER_BASE_COUNT, (u_char)0);

    /* Disable interrupts */
    DPRINTF(("ad1848_close: disable intrs\n"));
    ad_write(sc, SP_PIN_CONTROL, ad_read(sc, SP_PIN_CONTROL) & ~(INTERRUPT_ENABLE));

    DPRINTF(("ad1848_close: disable capture and playback\n"));
    r = ad_read(sc, SP_INTERFACE_CONFIG);
    r &= ~(CAPTURE_ENABLE|PLAYBACK_ENABLE);
    ad_write(sc, SP_INTERFACE_CONFIG, r);

#ifdef AUDIO_DEBUG
    if (ad1848debug)
	ad1848_dump_regs(sc);
#endif
}

/*
 * Lower-level routines
 */
int
ad1848_commit_settings(addr)
    void *addr;
{
    struct ad1848_softc *sc = addr;
    int timeout;
    u_char fs;
    int s = splaudio();
    
    ad1848_mute_monitor(sc, 1);
    
    ad_set_MCE(sc, 1);		/* Enables changes to the format select reg */

    fs = sc->speed_bits | (sc->format_bits << 5);

    if (sc->channels == 2)
	fs |= FMT_STEREO;

    ad_write(sc, SP_CLOCK_DATA_FORMAT, fs);

    /*
     * If mode == 2 (CS4231), set I28 also. It's the capture format register.
     */
    if (sc->mode == 2) {
	/* Gravis Ultrasound MAX SDK sources says something about errata
	 * sheets, with the implication that these inb()s are necessary.
	 */
	(void) inb(sc->sc_iobase+AD1848_IDATA);
	(void) inb(sc->sc_iobase+AD1848_IDATA);
	/*
	 * Write to I8 starts resyncronization. Wait until it completes.
	 */
	timeout = 100000;
	while (timeout > 0 && inb(sc->sc_iobase+AD1848_IADDR) == SP_IN_INIT)
	    timeout--;

	ad_write(sc, CS_REC_FORMAT, fs);
	/* Gravis Ultrasound MAX SDK sources says something about errata
	 * sheets, with the implication that these inb()s are necessary.
	 */
	(void) inb(sc->sc_iobase+AD1848_IDATA);
	(void) inb(sc->sc_iobase+AD1848_IDATA);
	/* Now wait for resync for capture side of the house */
    }
    /*
     * Write to I8 starts resyncronization. Wait until it completes.
     */
    timeout = 100000;
    while (timeout > 0 && inb(sc->sc_iobase+AD1848_IADDR) == SP_IN_INIT)
	timeout--;

    if (inb(sc->sc_iobase+AD1848_IADDR) == SP_IN_INIT)
	printf("ad1848_commit: Auto calibration timed out\n");

    /*
     * Starts the calibration process and
     * enters playback mode after it.
     */
    ad_set_MCE(sc, 0);
    wait_for_calibration(sc);

    ad1848_mute_monitor(sc, 0);

    sc->sc_lastcc = -1;

    splx(s);
    
    return 0;
}

void
ad1848_reset(sc)
    register struct ad1848_softc *sc;
{
#if 0
    u_char r;
#endif
    
    DPRINTF(("ad1848_reset\n"));
    
    /* Clear the PEN and CEN bits */
#if 0
    r = ad_read(sc, SP_INTERFACE_CONFIG);
    r &= ~(CAPTURE_ENABLE|PLAYBACK_ENABLE);
    ad_write(sc, SP_INTERFACE_CONFIG, r);
#else
    ad_write(sc, SP_INTERFACE_CONFIG, 0);
#endif
    if (sc->mode == 2) {
	    outb(sc->sc_iobase+AD1848_IADDR, CS_IRQ_STATUS);
	    outb(sc->sc_iobase+AD1848_IDATA, 0);
    }
    /* Clear interrupt status */
    outb(sc->sc_iobase+AD1848_STATUS, 0);
#ifdef AUDIO_DEBUG
    if (ad1848debug)
	ad1848_dump_regs(sc);
#endif
}

int
ad1848_set_speed(sc, arg)
    register struct ad1848_softc *sc;
    int arg;
{
    /*
     * The sampling speed is encoded in the least significant nible of I8. The
     * LSB selects the clock source (0=24.576 MHz, 1=16.9344 Mhz) and other
     * three bits select the divisor (indirectly):
     *
     * The available speeds are in the following table. Keep the speeds in
     * the increasing order.
     */
    typedef struct {
	int	speed;
	u_char	bits;
    } speed_struct;

    static speed_struct speed_table[] =  {
    {5510, (0 << 1) | 1},
    {5510, (0 << 1) | 1},
    {6620, (7 << 1) | 1},
    {8000, (0 << 1) | 0},
    {9600, (7 << 1) | 0},
    {11025, (1 << 1) | 1},
    {16000, (1 << 1) | 0},
    {18900, (2 << 1) | 1},
    {22050, (3 << 1) | 1},
    {27420, (2 << 1) | 0},
    {32000, (3 << 1) | 0},
    {33075, (6 << 1) | 1},
    {37800, (4 << 1) | 1},
    {44100, (5 << 1) | 1},
    {48000, (6 << 1) | 0}
    };

    int i, n, selected = -1;

    n = sizeof(speed_table) / sizeof(speed_struct);

    if (arg < speed_table[0].speed)
	selected = 0;
    if (arg > speed_table[n - 1].speed)
	selected = n - 1;

    for (i = 1 /*really*/ ; selected == -1 && i < n; i++)
	if (speed_table[i].speed == arg)
	    selected = i;
	else if (speed_table[i].speed > arg) {
	    int diff1, diff2;

	    diff1 = arg - speed_table[i - 1].speed;
	    diff2 = speed_table[i].speed - arg;

	    if (diff1 < diff2)
		selected = i - 1;
	    else
		selected = i;
	}

    if (selected == -1) {
	printf("ad1848: Can't find speed???\n");
	selected = 3;
    }

    sc->speed = speed_table[selected].speed;
    sc->speed_bits = speed_table[selected].bits;

    return sc->speed;
}

int
ad1848_set_format(sc, fmt, prec)
    register struct ad1848_softc *sc;
    int fmt, prec;
{
    static u_char format2bits[] =  {
      /* AUDIO_ENCODING_ULAW */   FMT_ULAW >> 5,
      /* AUDIO_ENCODING_ALAW */   FMT_ALAW >> 5, 
      /* AUDIO_ENCODING_PCM16 */  FMT_TWOS_COMP >> 5,
      /* AUDIO_ENCODING_PCM8 */   FMT_PCM8 >> 5
    };

    DPRINTF(("ad1848_set_format: fmt=%d prec=%d\n", fmt, prec));
    
    /* If not linear; force prec to 8bits */
    if (fmt != AUDIO_ENCODING_PCM16 && prec == 16)
	prec = 8;

    if (fmt < AUDIO_ENCODING_ULAW || fmt > AUDIO_ENCODING_PCM8)
	goto nogood;

    if (prec != 8 && prec != 16)
	goto nogood;
    
    sc->format_bits = format2bits[fmt-1];

    if (fmt == AUDIO_ENCODING_PCM16 && prec == 8)
	sc->format_bits = FMT_PCM8 >> 5;	/* signed vs. unsigned samples? */

    DPRINTF(("ad1848_set_format: bits=%x\n", sc->format_bits));

    return fmt;

 nogood:
    sc->format_bits = 0;
    return -1;
}

/*
 * Halt a DMA in progress.
 */
int
ad1848_halt_out_dma(addr)
    void *addr;
{
    register struct ad1848_softc *sc = addr;
    u_char reg;
	
    DPRINTF(("ad1848: ad1848_halt_out_dma\n"));

    reg = ad_read(sc, SP_INTERFACE_CONFIG);
    ad_write(sc, SP_INTERFACE_CONFIG, (reg & ~PLAYBACK_ENABLE));
    sc->sc_locked = 0;

    return(0);
}

int
ad1848_halt_in_dma(addr)
    void *addr;
{
    register struct ad1848_softc *sc = addr;
    u_char reg;
    
    DPRINTF(("ad1848: ad1848_halt_in_dma\n"));

    reg = ad_read(sc, SP_INTERFACE_CONFIG);
    ad_write(sc, SP_INTERFACE_CONFIG, (reg & ~CAPTURE_ENABLE));
    sc->sc_locked = 0;

    return(0);
}

int
ad1848_cont_out_dma(addr)
    void *addr;
{
    register struct ad1848_softc *sc = addr;
    u_char reg;
	
    DPRINTF(("ad1848: ad1848_cont_out_dma %s\n", sc->sc_locked?"(locked)":""));

    reg = ad_read(sc, SP_INTERFACE_CONFIG);
    ad_write(sc, SP_INTERFACE_CONFIG, (reg | PLAYBACK_ENABLE));

    return(0);
}

int
ad1848_cont_in_dma(addr)
    void *addr;
{
    register struct ad1848_softc *sc = addr;
    u_char reg;
	
    DPRINTF(("ad1848: ad1848_cont_in_dma %s\n", sc->sc_locked?"(locked)":""));

    reg = ad_read(sc, SP_INTERFACE_CONFIG);
    ad_write(sc, SP_INTERFACE_CONFIG, (reg | CAPTURE_ENABLE));

    return(0);
}

/*
 * DMA input/output are called at splaudio().
 */
int
ad1848_dma_input(addr, p, cc, intr, arg)
    void *addr;
    void *p;
    int cc;
    void (*intr) __P((void *));
    void *arg;
{
    register struct ad1848_softc *sc = addr;
    register u_char reg;
    
    if (sc->sc_locked) {
	DPRINTF(("ad1848_dma_input: locked\n"));
	return 0;
    }
    
#ifdef AUDIO_DEBUG
    if (ad1848debug > 1)
	Dprintf("ad1848_dma_input: cc=%d 0x%x (0x%x)\n", cc, intr, arg);
#endif
    sc->sc_locked = 1;
    sc->sc_intr = intr;
    sc->sc_arg = arg;
    sc->sc_dma_flags = DMAMODE_READ;
    sc->sc_dma_bp = p;
    sc->sc_dma_cnt = cc;
    isa_dmastart(DMAMODE_READ, p, cc, sc->sc_recdrq);

    if (sc->precision == 16)
	cc >>= 1;
	
    if (sc->channels == 2)
	cc >>= 1;
    cc--;
    
    if (sc->sc_lastcc != cc || sc->sc_mode != AUMODE_RECORD) {
	ad_write(sc, SP_LOWER_BASE_COUNT, (u_char)(cc & 0xff));
	ad_write(sc, SP_UPPER_BASE_COUNT, (u_char)((cc >> 8) & 0xff));

	if (sc->mode == 2) {
	    ad_write(sc, CS_LOWER_REC_CNT, (u_char)(cc & 0xff));
	    ad_write(sc, CS_UPPER_REC_CNT, (u_char)((cc >> 8) & 0xff));
        }

	reg = ad_read(sc, SP_INTERFACE_CONFIG);
	ad_write(sc, SP_INTERFACE_CONFIG, (CAPTURE_ENABLE|reg));

	sc->sc_lastcc = cc;
	sc->sc_mode = AUMODE_RECORD;
    }
    
    return 0;
}

int
ad1848_dma_output(addr, p, cc, intr, arg)
    void *addr;
    void *p;
    int cc;
    void (*intr) __P((void *));
    void *arg;
{
    register struct ad1848_softc *sc = addr;
    register u_char reg;
    
    if (sc->sc_locked) {
	DPRINTF(("ad1848_dma_output: locked\n"));
	return 0;
    }
    
#ifdef AUDIO_DEBUG
    if (ad1848debug > 1)
	Dprintf("ad1848_dma_output: cc=%d 0x%x (0x%x)\n", cc, intr, arg);
#endif
    sc->sc_locked = 1;
    sc->sc_intr = intr;
    sc->sc_arg = arg;
    sc->sc_dma_flags = DMAMODE_WRITE;
    sc->sc_dma_bp = p;
    sc->sc_dma_cnt = cc;
    isa_dmastart(DMAMODE_WRITE, p, cc, sc->sc_drq);
    
    if (sc->precision == 16)
	cc >>= 1;
	
    if (sc->channels == 2)
	cc >>= 1;
    cc--;

    if (sc->sc_lastcc != cc || sc->sc_mode != AUMODE_PLAY) {
	ad_write(sc, SP_LOWER_BASE_COUNT, (u_char)(cc & 0xff));
	ad_write(sc, SP_UPPER_BASE_COUNT, (u_char)((cc >> 8) & 0xff));
	reg = ad_read(sc, SP_INTERFACE_CONFIG);
	ad_write(sc, SP_INTERFACE_CONFIG, (PLAYBACK_ENABLE|reg));
	sc->sc_lastcc = cc;
	sc->sc_mode = AUMODE_PLAY;
    }
    
    return 0;
}

int
ad1848_intr(arg)
	void *arg;
{
    register struct ad1848_softc *sc = arg;
    int retval = 0;
    u_char status;
    
    /* Get intr status */
    status = inb(sc->sc_iobase+AD1848_STATUS);
    
#ifdef AUDIO_DEBUG
    if (ad1848debug > 1)
	Dprintf("ad1848_intr: intr=0x%x status=%x\n", sc->sc_intr, status);
#endif
    sc->sc_locked = 0;
    sc->sc_interrupts++;
    
    /* Handle interrupt */
    if (sc->sc_intr && (status & INTERRUPT_STATUS)) {
	/* ACK DMA read because it may be in a bounce buffer */
	/* XXX Do write to mask DMA ? */
	if (sc->sc_dma_flags & DMAMODE_READ)
	    isa_dmadone(sc->sc_dma_flags, sc->sc_dma_bp, sc->sc_dma_cnt - 1, sc->sc_recdrq);
	(*sc->sc_intr)(sc->sc_arg);
	retval = 1;
    }

    /* clear interrupt */
    if (status & INTERRUPT_STATUS)
	outb(sc->sc_iobase+AD1848_STATUS, 0);

    return(retval);
}