root/usr/src/cmd/audio/utilities/device_ctl.c
/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (the "License").  You may not use this file except in compliance
 * with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright 1989-2003 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

/*
 * This file contains routines to read and write the audio device state.
 */

#include <errno.h>
#include <stropts.h>
#include <sys/types.h>
#include <sys/file.h>
#include <sys/stat.h>
#include <sys/ioctl.h>

#include <libaudio_impl.h>
#include <audio_errno.h>
#include <audio_hdr.h>
#include <audio_device.h>


/*
 * Get device information structure.
 */
int
audio_getinfo(int fd, Audio_info *ip)
{
        if (ioctl(fd, AUDIO_GETINFO, (char *)ip) < 0) {
                return (AUDIO_UNIXERROR);
        } else {
                return (AUDIO_SUCCESS);
        }
}

/*
 * Set device information structure.
 * The calling routine should use AUDIO_INITINFO prior to setting new values.
 */
int
audio_setinfo(int fd, Audio_info *ip)
{
        if (ioctl(fd, AUDIO_SETINFO, (char *)ip) < 0) {
                return (AUDIO_UNIXERROR);
        } else {
                return (AUDIO_SUCCESS);
        }
}

/*
 * Return an Audio_hdr corresponding to the encoding configuration
 * of the audio device on 'fd'.
 */
int
audio__setplayhdr(int fd, Audio_hdr *hdrp, unsigned int which)
{
        Audio_hdr               thdr;
        Audio_info              info;
        struct audio_prinfo     *prinfo;
        int                     err;

        if (which & AUDIO__PLAY)
                prinfo = &info.play;
        else if (which & AUDIO__RECORD)
                prinfo = &info.record;
        else
                return (AUDIO_ERR_BADARG);

        if (which & AUDIO__SET) {
                thdr = *hdrp;                   /* save original hdr */
                AUDIO_INITINFO(&info);
                prinfo->sample_rate = hdrp->sample_rate;
                prinfo->channels = hdrp->channels;
                prinfo->encoding = hdrp->encoding;
                prinfo->precision = hdrp->bytes_per_unit * 8;
                err = audio_setinfo(fd, &info);
        } else {
                err = audio_getinfo(fd, &info);
        }

        /* Decode back into the header structure */
        /* since the I_SMSG is set, upon completion of updating         */
        /* the format, the driver sends the msg  so the                 */
        /* system call is interrupted.  For now, just ignore this       */
        if ((err == AUDIO_SUCCESS) || (errno == EINTR)) {
                hdrp->sample_rate = prinfo->sample_rate;
                hdrp->channels = prinfo->channels;
                hdrp->data_size = AUDIO_UNKNOWN_SIZE;
                hdrp->encoding = prinfo->encoding;
                switch (hdrp->encoding) {
                case AUDIO_ENCODING_ULAW:
                case AUDIO_ENCODING_ALAW:
                case AUDIO_ENCODING_LINEAR:
                case AUDIO_ENCODING_LINEAR8:
                case AUDIO_ENCODING_FLOAT:
                        hdrp->bytes_per_unit = prinfo->precision / 8;
                        hdrp->samples_per_unit = 1;
                        break;
                default:
                        return (AUDIO_ERR_ENCODING);
                }
                if (which & AUDIO__SET) {
                        /* Check to see if *all* changes took effect */
                        if (audio_cmp_hdr(hdrp, &thdr) != 0)
                                return (AUDIO_ERR_NOEFFECT);
                }
        }
        return (err);
}


/*
 * Attempt to configure the audio device to match a particular encoding.
 */

/*
 * Set and/or set individual state values.
 * This routine is generally invoked by using the audio_set_*()
 * and audio_get_*() macros.
 * The 'valp' argument is always a pointer to an unsigned int.
 * Conversions to/from (unsigned char) flags are taken care of.
 */
int
audio__setval(int fd, unsigned int *valp, unsigned int which)
{
        Audio_info              info;
        struct audio_prinfo     *prinfo;
        int                     err;
        unsigned                *up;
        unsigned char           *cp;

        /* Set a pointer to the value of interest */
        if (which & AUDIO__PLAY)
                prinfo = &info.play;
        else if (which & AUDIO__RECORD)
                prinfo = &info.record;
        else if ((which & AUDIO__SETVAL_MASK) != AUDIO__MONGAIN)
                return (AUDIO_ERR_BADARG);

        up = NULL;
        switch (which & AUDIO__SETVAL_MASK) {
        case AUDIO__PORT:
                up = &prinfo->port; break;
        case AUDIO__SAMPLES:
                up = &prinfo->samples; break;
        case AUDIO__ERROR:
                cp = &prinfo->error; break;
        case AUDIO__EOF:
                up = &prinfo->eof; break;
        case AUDIO__OPEN:
                cp = &prinfo->open; break;
        case AUDIO__ACTIVE:
                cp = &prinfo->active; break;
        case AUDIO__WAITING:
                cp = &prinfo->waiting; break;
        case AUDIO__GAIN:
                up = &prinfo->gain; break;
        case AUDIO__MONGAIN:
                up = &info.monitor_gain; break;
        case AUDIO__BALANCE:
                cp = &prinfo->balance; break;
        default:
                return (AUDIO_ERR_BADARG);
        }

        if (which & AUDIO__SET) {
                /* Init so that only the value of interest is changed */
                AUDIO_INITINFO(&info);
                if (up != NULL) {
                        *up = *valp;
                } else {
                        *cp = (unsigned char) *valp;
                }
                err = audio_setinfo(fd, &info);
        } else {
                err = audio_getinfo(fd, &info);
        }
        if (err == AUDIO_SUCCESS) {
                if (up != NULL)
                        *valp = *up;
                else
                        *valp = (unsigned)*cp;
        }
        return (err);
}

/*
 * Get/set gain value.
 * NOTE: legal values are floating-point double 0. - 1.
 */
int
audio__setgain(int fd, double *valp, unsigned int which)
{
        int             err;
        unsigned        x;

        if (which & AUDIO__SET) {
                if ((*valp < 0.) || (*valp > 1.))
                        return (AUDIO_ERR_BADARG);

                /* Map value into legal range */
                x = ((unsigned)(*valp * (AUDIO_MAX_GAIN - AUDIO_MIN_GAIN))) +
                    AUDIO_MIN_GAIN;
        }

        /* Get or set the new value */
        err = audio__setval(fd, &x, which);
        if (err == AUDIO_SUCCESS) {
                /* Map value back to double */
                *valp = ((double)(x - AUDIO_MIN_GAIN) /
                    (AUDIO_MAX_GAIN - AUDIO_MIN_GAIN));
        }
        return (err);
}

/*
 * Set Pause/resume flags.
 * Can set play and record individually or together.
 */
int
audio__setpause(int fd, unsigned int which)
{
        Audio_info      info;
        int             err;
        unsigned char   x;

        AUDIO_INITINFO(&info);

        if ((which & AUDIO__SETVAL_MASK) == AUDIO__PAUSE) {
                x = TRUE;
        } else if ((which & AUDIO__SETVAL_MASK) == AUDIO__RESUME) {
                x = FALSE;
        } else {
                return (AUDIO_ERR_BADARG);
        }

        if (which & AUDIO__PLAY) {
                info.play.pause = x;
        }
        if (which & AUDIO__RECORD) {
                info.record.pause = x;
        }

        /* Set the new value */
        err = audio_setinfo(fd, &info);

        /* Check to see if this took effect */
        if (err == AUDIO_SUCCESS) {
                if (((which & AUDIO__PLAY) && (info.play.pause != x)) ||
                    ((which & AUDIO__RECORD) && (info.record.pause != x)))
                        return (AUDIO_ERR_NOEFFECT);
        }
        return (err);
}


/*
 * Flush play and/or record buffers.
 */
int
audio__flush(int fd, unsigned int which)
{
        int             flag;

        flag = (which & AUDIO__PLAY) ? FLUSHW : 0;
        flag |= (which & AUDIO__RECORD) ? FLUSHR : 0;

        return ((ioctl(fd, I_FLUSH, flag) < 0) ?
            AUDIO_UNIXERROR : AUDIO_SUCCESS);
}


/*
 * Wait synchronously for output buffers to finish playing.
 * If 'sig' is TRUE, signals may interrupt the drain.
 */
int
audio_drain(int fd, int sig)
{
        while (ioctl(fd, AUDIO_DRAIN, 0) < 0) {
                if (errno != EINTR) {
                        return (AUDIO_UNIXERROR);
                }

                if (sig) {
                        return (AUDIO_ERR_INTERRUPTED);
                }
        }
        return (AUDIO_SUCCESS);
}

/*
 * Write an EOF marker to the output audio stream.
 */
int
audio_play_eof(int fd)
{
        return (write(fd, (char *)NULL, 0) < 0 ?
            AUDIO_UNIXERROR : AUDIO_SUCCESS);
}