/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (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 (c) 2009, 2010, Oracle and/or its affiliates. All rights reserved.
 */

/*
 * Sun audio(4I) and mixer(4I) personality.
 *
 * There are some "undocumented" details of how legacy Sun audio
 * interfaces work.  The following "rules" were derived from reading the
 * legacy Sun mixer code, and to the best of our knowledge are not
 * documented elsewhere.
 *
 * - We create a "fake" audio device, which behaves like a classic
 *   exclusive audio device, for each PID, as determined during open(2).
 *
 * - Different processes don't interfere with each other.  Even though
 *   they are running concurrently, they each think they have exclusive
 *   control over the audio device.
 *
 * - Read and write directions operate independent of each other.  That
 *   is, a device open for reading won't intefere with a future open for
 *   writing, and vice versa.  This is true even within the same process.
 *
 * - Because the virtualization is by PID, strange behavior may occur
 *   if a process tries to open an audio device at the same time it
 *   has already received a file descriptor from another process (such
 *   through inheritence via fork()).
 *
 * - The "fake" audio device has no control over physical settings.
 *   It sees only the software attenuation-based volumes for play and
 *   record, and has no support for alternate input or output ports or
 *   access to the monitoring features of the hardware.
 *
 * - Explicit notificaton signals (SIGPOLL) are only ever sent up the
 *   audioctl node -- never up a regular audio node.  (The stream head
 *   may still issue SIGPOLL based on readability/writability of
 *   course.)
 *
 * - Corollary: processes that want asynch. notifications will open
 *   /dev/audioctl as well as /dev/audio.
 *
 * - We don't support the MIXER mode at all.
 *
 * - By corollary, a process is only allowed to open /dev/audio once
 *   (in each direction.)
 *
 * - Attempts to open /dev/audio in duplex mode (O_RDWR) fail (EBUSY)
 *   if the device cannot support duplex operation.
 *
 * - Attempts to open a device with FREAD set fail if the device is not
 *   capable of recording.  (Likewise for FWRITE and playback.)
 *
 * - No data transfer is permitted for audioctl nodes.  (No actual
 *   record or play.)
 *
 * - Sun audio does not support any formats other than linear and
 *   ULAW/ALAW.  I.e. it will never support AC3 or other "opaque"
 *   streams which require special handling.
 *
 * - Sun audio only supports stereo or monophonic data streams.
 */

#include <sys/types.h>
#include <sys/open.h>
#include <sys/errno.h>
#include <sys/audio.h>
#include <sys/mixer.h>
#include <sys/file.h>
#include <sys/stropts.h>
#include <sys/strsun.h>
#include <sys/sysmacros.h>
#include <sys/list.h>
#include <sys/note.h>
#include <sys/stat.h>
#include <sys/ddi.h>
#include <sys/sunddi.h>
#include "audio_client.h"

typedef struct daclient daclient_t;
typedef struct dadev dadev_t;
typedef struct daproc daproc_t;

/* common structure shared between both audioctl and audio nodes */
struct daclient {
        daproc_t                *dc_proc;
        dadev_t                 *dc_dev;
        audio_client_t          *dc_client;
        queue_t                 *dc_wq;
        unsigned                dc_eof;
        list_t                  dc_eofcnt;
        kmutex_t                dc_lock;
        mblk_t                  *dc_draining;
};

struct eofcnt {
        list_node_t             linkage;
        uint64_t                tail;
};

struct dadev {
        audio_dev_t             *d_dev;

        list_t                  d_procs;
        kmutex_t                d_mx;
        kcondvar_t              d_cv;
};

struct daproc {
        pid_t                   p_id;
        struct audio_info       p_info;
        int                     p_refcnt;
        int                     p_oflag;
        list_node_t             p_linkage;
        dadev_t                 *p_dev;
        audio_client_t          *p_writer;
        audio_client_t          *p_reader;
};

int devaudio_proc_hold(audio_client_t *, int);
void devaudio_proc_release(audio_client_t *);
static void devaudio_proc_update(daproc_t *);


static int
devaudio_compose_format(audio_prinfo_t *prinfo)
{
        switch (prinfo->precision) {
        case 8:
                switch (prinfo->encoding) {
                case AUDIO_ENCODING_ULAW:
                        return (AUDIO_FORMAT_ULAW);
                case AUDIO_ENCODING_ALAW:
                        return (AUDIO_FORMAT_ALAW);
                case AUDIO_ENCODING_LINEAR8:
                        return (AUDIO_FORMAT_U8);
                case AUDIO_ENCODING_LINEAR:
                        return (AUDIO_FORMAT_S8);
                }
                break;
        case 16:
                if (prinfo->encoding == AUDIO_ENCODING_LINEAR)
                        return (AUDIO_FORMAT_S16_NE);
                break;
        case 32:
                if (prinfo->encoding == AUDIO_ENCODING_LINEAR)
                        return (AUDIO_FORMAT_S32_NE);
                break;
        }
        return (AUDIO_FORMAT_NONE);

}

static void
devaudio_decompose_format(audio_prinfo_t *prinfo, int afmt)
{
        int     e, p;

        /*
         * N.B.: Even though some of the formats below can't be set by
         * this personality, reporting them (using the closest match)
         * allows this personality to roughly approximate settings for
         * other streams.  It would be incredibly poor form for any
         * personality to modify the format settings for a different
         * personality, so we don't worry about that case.
         */

        switch (afmt) {
        case AUDIO_FORMAT_ULAW:
                e = AUDIO_ENCODING_ULAW;
                p = 8;
                break;

        case AUDIO_FORMAT_ALAW:
                e = AUDIO_ENCODING_ALAW;
                p = 8;
                break;

        case AUDIO_FORMAT_U8:
                e = AUDIO_ENCODING_LINEAR8;
                p = 8;
                break;

        case AUDIO_FORMAT_S8:
                e = AUDIO_ENCODING_LINEAR;
                p = 8;
                break;

        case AUDIO_FORMAT_S16_NE:
        case AUDIO_FORMAT_S16_OE:
        case AUDIO_FORMAT_U16_NE:
        case AUDIO_FORMAT_U16_OE:
                e = AUDIO_ENCODING_LINEAR;
                p = 16;
                break;

        case AUDIO_FORMAT_S24_NE:
        case AUDIO_FORMAT_S24_OE:
        case AUDIO_FORMAT_S24_PACKED:
                e = AUDIO_ENCODING_LINEAR;
                p = 24;
                break;

        case AUDIO_FORMAT_S32_NE:
        case AUDIO_FORMAT_S32_OE:
                e = AUDIO_ENCODING_LINEAR;
                p = 32;
                break;

        default:
                /* all other formats (e.g. AC3) are uninterpreted */
                e = AUDIO_ENCODING_NONE;
                p = 32;
                break;
        }

        prinfo->encoding = e;
        prinfo->precision = p;
}

static daproc_t *
devaudio_proc_alloc(audio_client_t *c)
{
        audio_info_t    *info;
        audio_prinfo_t  *prinfo;
        uint32_t        caps;
        daproc_t        *proc;

        if ((proc = kmem_zalloc(sizeof (*proc), KM_NOSLEEP)) == NULL) {
                return (NULL);
        }
        info = &proc->p_info;

        /*
         * audio(4I) says: Upon the initial open() of the audio
         * device, the driver resets the data format of the device to
         * the default state of 8-bit, 8Khz, mono u-Law data.
         */
        prinfo = &info->play;
        prinfo->channels =      1;
        prinfo->sample_rate =   8000;
        prinfo->encoding =      AUDIO_ENCODING_ULAW;
        prinfo->precision =     8;
        prinfo->gain =          AUDIO_MAX_GAIN;
        prinfo->balance =       AUDIO_MID_BALANCE;
        prinfo->buffer_size =   8192;
        prinfo->pause =         B_FALSE;
        prinfo->waiting =       B_FALSE;
        prinfo->open =          B_FALSE;
        prinfo->active =        B_FALSE;
        prinfo->samples =       0;
        prinfo->eof =           0;
        prinfo->error =         0;
        prinfo->minordev =      0;
        prinfo->port =          AUDIO_SPEAKER;
        prinfo->avail_ports =   AUDIO_SPEAKER;
        prinfo->mod_ports =     AUDIO_NONE;
        prinfo->_xxx =          0;

        prinfo = &info->record;
        prinfo->channels =      1;
        prinfo->sample_rate =   8000;
        prinfo->encoding =      AUDIO_ENCODING_ULAW;
        prinfo->precision =     8;
        prinfo->gain =          AUDIO_MAX_GAIN;
        prinfo->balance =       AUDIO_MID_BALANCE;
        prinfo->buffer_size =   8192;
        prinfo->waiting =       B_FALSE;
        prinfo->open =          B_FALSE;
        prinfo->active =        B_FALSE;
        prinfo->samples =       0;
        prinfo->eof =           0;
        prinfo->error =         0;
        prinfo->minordev =      0;
        prinfo->port =          AUDIO_MICROPHONE;
        prinfo->avail_ports =   AUDIO_MICROPHONE;
        prinfo->mod_ports =     AUDIO_MICROPHONE;

        info->output_muted =    B_FALSE;
        /* pretend we don't have a software mixer - we don't support the API */
        info->hw_features =     0;
        info->sw_features =     0;
        info->sw_features_enabled = 0;

        caps = auclnt_get_dev_capab(auclnt_get_dev(c));
        if (caps & AUDIO_CLIENT_CAP_PLAY)
                info->hw_features |= AUDIO_HWFEATURE_PLAY;
        if (caps & AUDIO_CLIENT_CAP_RECORD)
                info->hw_features |= AUDIO_HWFEATURE_RECORD;
        if (caps & AUDIO_CLIENT_CAP_DUPLEX)
                info->hw_features |= AUDIO_HWFEATURE_DUPLEX;

        return (proc);
}

static void
devaudio_proc_free(daproc_t *proc)
{
        kmem_free(proc, sizeof (*proc));
}

int
devaudio_proc_hold(audio_client_t *c, int oflag)
{
        pid_t           pid;
        daproc_t        *proc;
        dadev_t         *dev;
        daclient_t      *dc;
        list_t          *l;
        audio_dev_t     *adev;
        int             rv;

        adev = auclnt_get_dev(c);

        /* first allocate and initialize the daclient private data */
        if ((dc = kmem_zalloc(sizeof (*dc), KM_NOSLEEP)) == NULL) {
                return (ENOMEM);
        }

        mutex_init(&dc->dc_lock, NULL, MUTEX_DRIVER, NULL);
        list_create(&dc->dc_eofcnt, sizeof (struct eofcnt),
            offsetof(struct eofcnt, linkage));
        auclnt_set_private(c, dc);

        dev = auclnt_get_dev_minor_data(adev, AUDIO_MINOR_DEVAUDIO);
        l = &dev->d_procs;
        pid = auclnt_get_pid(c);

        /* set a couple of common fields */
        dc->dc_client = c;
        dc->dc_dev = dev;

        mutex_enter(&dev->d_mx);
        for (proc = list_head(l); proc != NULL; proc = list_next(l, proc)) {
                if (proc->p_id == pid) {
                        proc->p_refcnt++;
                        break;
                }
        }
        if (proc == NULL) {
                if ((proc = devaudio_proc_alloc(c)) == NULL) {
                        rv = ENOMEM;
                        goto failed;
                }
                proc->p_refcnt = 1;
                proc->p_id = pid;
                proc->p_dev = dev;
                list_insert_tail(l, proc);
        }

        while (proc->p_oflag & oflag) {

                if (oflag & (FNDELAY|FNONBLOCK)) {
                        rv = EBUSY;
                        goto failed;
                }
                if (oflag & FWRITE)
                        proc->p_info.play.waiting++;
                if (oflag & FREAD)
                        proc->p_info.record.waiting++;
                if (cv_wait_sig(&dev->d_cv, &dev->d_mx) == 0) {
                        /* interrupted! */
                        if (oflag & FWRITE)
                                proc->p_info.play.waiting--;
                        if (oflag & FREAD)
                                proc->p_info.record.waiting--;
                        rv = EINTR;
                        goto failed;
                }
                if (oflag & FWRITE)
                        proc->p_info.play.waiting--;
                if (oflag & FREAD)
                        proc->p_info.record.waiting--;
        }

        if (oflag & FWRITE) {
                audio_prinfo_t  *play = &proc->p_info.play;
                audio_stream_t  *sp = auclnt_output_stream(c);

                if (((rv = auclnt_set_rate(sp, 8000)) != 0) ||
                    ((rv = auclnt_set_format(sp, AUDIO_FORMAT_ULAW)) != 0) ||
                    ((rv = auclnt_set_channels(sp, 1)) != 0)) {
                        goto failed;
                }

                auclnt_set_samples(sp, 0);
                auclnt_set_errors(sp, 0);
                play->eof = 0;
                play->buffer_size = 8192;

                auclnt_set_gain(sp, ((play->gain * 100) / AUDIO_MAX_GAIN));
                auclnt_set_muted(sp, proc->p_info.output_muted);
                play->open = B_TRUE;
                proc->p_writer = c;
                proc->p_oflag |= FWRITE;
        }

        if (oflag & FREAD) {
                audio_prinfo_t  *rec = &proc->p_info.record;
                audio_stream_t  *sp = auclnt_input_stream(c);

                if (((rv = auclnt_set_rate(sp, 8000)) != 0) ||
                    ((rv = auclnt_set_format(sp, AUDIO_FORMAT_ULAW)) != 0) ||
                    ((rv = auclnt_set_channels(sp, 1)) != 0)) {
                        goto failed;
                }

                auclnt_set_samples(sp, 0);
                auclnt_set_errors(sp, 0);
                rec->eof = 0;
                rec->buffer_size = 8192;

                auclnt_set_gain(sp, ((rec->gain * 100) / AUDIO_MAX_GAIN));
                rec->open = B_TRUE;
                proc->p_reader = c;
                proc->p_oflag |= FREAD;
        }


        dc->dc_wq = auclnt_get_wq(c);

        /* we update the s_proc last to avoid a race */
        dc->dc_proc = proc;

        devaudio_proc_update(proc);

        mutex_exit(&dev->d_mx);

        return (0);

failed:
        mutex_exit(&dev->d_mx);
        devaudio_proc_release(c);
        return (rv);

}

static void
devaudio_clear_eof(audio_client_t *c)
{
        struct eofcnt   *eof;
        daclient_t      *dc;

        dc = auclnt_get_private(c);
        mutex_enter(&dc->dc_lock);
        while ((eof = list_remove_head(&dc->dc_eofcnt)) != NULL) {
                kmem_free(eof, sizeof (*eof));
        }
        mutex_exit(&dc->dc_lock);
}

void
devaudio_proc_release(audio_client_t *c)
{
        daproc_t        *proc;
        dadev_t         *dev;
        mblk_t          *mp;
        daclient_t      *dc;

        dc = auclnt_get_private(c);
        proc = dc->dc_proc;
        dev = dc->dc_dev;
        dc->dc_proc = NULL;

        mutex_enter(&dev->d_mx);

        if (proc != NULL) {
                proc->p_refcnt--;
                ASSERT(proc->p_refcnt >= 0);

                if (c == proc->p_writer) {
                        proc->p_oflag &= ~FWRITE;
                        proc->p_writer = NULL;
                }
                if (c == proc->p_reader) {
                        proc->p_oflag &= ~FREAD;
                        proc->p_reader = NULL;
                }
                cv_broadcast(&dev->d_cv);

                if (proc->p_refcnt == 0) {
                        list_remove(&dev->d_procs, proc);
                        devaudio_proc_free(proc);
                }
                dc->dc_proc = NULL;
        }

        mutex_exit(&dev->d_mx);

        devaudio_clear_eof(c);

        while ((mp = dc->dc_draining) != NULL) {
                dc->dc_draining = mp->b_next;
                mp->b_next = NULL;
                freemsg(mp);
        }

        mutex_destroy(&dc->dc_lock);
        list_destroy(&dc->dc_eofcnt);
        kmem_free(dc, sizeof (*dc));
}

static void
devaudio_input(audio_client_t *c)
{
        audio_stream_t  *sp = auclnt_input_stream(c);
        daclient_t      *dc = auclnt_get_private(c);
        unsigned        framesz = auclnt_get_framesz(sp);
        queue_t         *rq = auclnt_get_rq(c);
        mblk_t          *mp;
        unsigned        nbytes = dc->dc_proc->p_info.record.buffer_size;
        unsigned        count = nbytes / framesz;

        /*
         * Potentially send a message upstream with the record data.
         * We collect this up in chunks of the buffer size requested
         * by the client.
         */

        while (auclnt_get_count(sp) >= count) {

                if ((!canput(rq)) ||
                    ((mp = allocb(nbytes, BPRI_MED)) == NULL)) {
                        /*
                         * This will apply back pressure to the
                         * buffer.  We haven't yet lost any data, we
                         * just can't send it up.  The point at which
                         * we have an unrecoverable overrun is in the
                         * buffer, not in the streams queue.  So, no
                         * need to do anything right now.
                         *
                         * Note that since recording is enabled, we
                         * expect that the callback routine will be
                         * called repeatedly & regularly, so we don't
                         * have to worry about leaving data orphaned
                         * in the queue.
                         */
                        break;
                }

                (void) auclnt_consume_data(sp, (caddr_t)mp->b_wptr, count);
                mp->b_wptr += nbytes;
                (void) putq(rq, mp);
        }
}

static void
devaudio_proc_update(daproc_t *proc)
{
        audio_info_t    *info;
        audio_stream_t  *sp;
        audio_client_t  *c;

        info = &proc->p_info;

        ASSERT(mutex_owned(&proc->p_dev->d_mx));

        if ((c = proc->p_writer) != NULL) {
                sp = auclnt_output_stream(c);

                info->play.sample_rate = auclnt_get_rate(sp);
                info->play.channels = auclnt_get_channels(sp);
                devaudio_decompose_format(&info->play, auclnt_get_format(sp));

                info->play.gain =
                    (auclnt_get_gain(sp) * AUDIO_MAX_GAIN) / 100;
                info->play.pause = auclnt_is_paused(sp);
                info->play.active = auclnt_is_running(sp);
                info->play.samples = auclnt_get_samples(sp);
                info->play.error = auclnt_get_errors(sp) ? B_TRUE : B_FALSE;
                info->output_muted = auclnt_get_muted(sp);
        } else {
                info->play.encoding = AUDIO_ENCODING_NONE;
                info->play.precision = 0;
                info->play.sample_rate = 0;
                info->play.pause = B_FALSE;
                info->play.active = B_FALSE;
                info->play.error = B_FALSE;
                info->play.samples = 0;
        }

        if ((c = proc->p_reader) != NULL) {
                sp = auclnt_input_stream(c);

                info->record.sample_rate = auclnt_get_rate(sp);
                info->record.channels = auclnt_get_channels(sp);
                devaudio_decompose_format(&info->record, auclnt_get_format(sp));

                info->record.gain =
                    (auclnt_get_gain(sp) * AUDIO_MAX_GAIN) / 100;
                info->record.pause = auclnt_is_paused(sp);
                info->record.active = auclnt_is_running(sp);
                info->record.samples = auclnt_get_samples(sp);
                info->record.error = auclnt_get_errors(sp) ? B_TRUE : B_FALSE;
        } else {
                info->record.encoding = AUDIO_ENCODING_NONE;
                info->record.precision = 0;
                info->record.sample_rate = 0;
                info->record.pause = B_FALSE;
                info->record.active = B_FALSE;
                info->record.error = B_FALSE;
                info->record.samples = 0;
        }
}

static void
devaudio_ioc_getinfo(queue_t *wq, audio_client_t *c, mblk_t *mp)
{
        daclient_t      *dc = auclnt_get_private(c);
        daproc_t        *proc = dc->dc_proc;
        mblk_t          *bcont;

        if ((bcont = allocb(sizeof (audio_info_t), BPRI_MED)) == NULL) {
                miocnak(wq, mp, 0, ENOMEM);
                return;
        }

        mutex_enter(&dc->dc_dev->d_mx);
        devaudio_proc_update(proc);
        bcopy(&proc->p_info, bcont->b_wptr, sizeof (audio_info_t));
        mutex_exit(&dc->dc_dev->d_mx);

        bcont->b_wptr += sizeof (audio_info_t);

        mcopyout(mp, NULL, sizeof (audio_info_t), NULL, bcont);
        qreply(wq, mp);
}

#define CHANGED(new, old, field)                        \
        ((new->field != ((uint32_t)~0)) && (new->field != old->field))
#define CHANGED8(new, old, field)                       \
        ((new->field != ((uint8_t)~0)) && (new->field != old->field))

static void
devaudio_ioc_setinfo(queue_t *wq, audio_client_t *c, mblk_t *mp)
{
        daclient_t      *dc;
        daproc_t        *proc;
        audio_info_t    *oinfo;
        audio_info_t    *ninfo;
        audio_prinfo_t  *npr;
        audio_prinfo_t  *opr;

        int             pfmt = AUDIO_FORMAT_NONE;
        int             rfmt = AUDIO_FORMAT_NONE;

        boolean_t       reader;
        boolean_t       writer;
        boolean_t       isctl;
        audio_stream_t  *sp;
        int             rv;
        caddr_t         uaddr;
        mblk_t          *bcont;

        struct copyresp *csp;

        if (DB_TYPE(mp) == M_IOCTL) {
                /* the special value "1" indicates that this is a copyin */
                uaddr = *(caddr_t *)(void *)mp->b_cont->b_rptr;

                mcopyin(mp, uaddr, sizeof (audio_info_t), NULL);
                qreply(wq, mp);
                return;
        }

        ASSERT(DB_TYPE(mp) == M_IOCDATA);
        if (((bcont = mp->b_cont) == NULL) ||
            (MBLKL(mp->b_cont) != sizeof (audio_info_t))) {
                miocnak(wq, mp, 0, EINVAL);
                return;
        }

        mp->b_cont = NULL;
        csp = (void *)mp->b_rptr;
        uaddr = (void *)csp->cp_private;
        dc = auclnt_get_private(c);
        ninfo = (void *)bcont->b_rptr;

        mutex_enter(&dc->dc_dev->d_mx);

        proc = dc->dc_proc;
        oinfo = &proc->p_info;

        if (auclnt_get_minor_type(c) == AUDIO_MINOR_DEVAUDIOCTL) {
                /* control node can do both read and write fields */
                isctl = B_TRUE;
                reader = B_TRUE;
                writer = B_TRUE;
        } else {
                isctl = B_FALSE;
                writer = (c == proc->p_writer);
                reader = (c == proc->p_reader);
        }

        /*
         * Start by validating settings.
         */
        npr = &ninfo->play;
        opr = &oinfo->play;

        if (writer && CHANGED(npr, opr, sample_rate)) {
                if ((isctl) ||
                    (npr->sample_rate < 5500) || (npr->sample_rate > 48000)) {
                        rv = EINVAL;
                        goto err;
                }
        }
        if (writer && CHANGED(npr, opr, channels)) {
                if ((isctl) || (npr->channels < 1) || (npr->channels > 2)) {
                        rv = EINVAL;
                        goto err;
                }
        }
        if (writer &&
            (CHANGED(npr, opr, encoding) || CHANGED(npr, opr, precision))) {
                if (npr->encoding == (uint32_t)~0)
                        npr->encoding = opr->encoding;
                if (npr->precision == (uint32_t)~0)
                        npr->precision = opr->precision;
                pfmt = devaudio_compose_format(npr);
                if ((isctl) || (pfmt == AUDIO_FORMAT_NONE)) {
                        rv = EINVAL;
                        goto err;
                }
        }

        /* play fields that anyone can modify */
        if (CHANGED(npr, opr, gain)) {
                if (npr->gain > AUDIO_MAX_GAIN) {
                        rv = EINVAL;
                        goto err;
                }
        }


        npr = &ninfo->record;
        opr = &oinfo->record;

        if (reader && CHANGED(npr, opr, sample_rate)) {
                if ((isctl) ||
                    (npr->sample_rate < 5500) || (npr->sample_rate > 48000)) {
                        rv = EINVAL;
                        goto err;
                }
        }
        if (reader && CHANGED(npr, opr, channels)) {
                if ((isctl) || (npr->channels < 1) || (npr->channels > 2)) {
                        rv = EINVAL;
                        goto err;
                }
        }
        if (reader &&
            (CHANGED(npr, opr, encoding) || CHANGED(npr, opr, precision))) {
                if (npr->encoding == (uint32_t)~0)
                        npr->encoding = opr->encoding;
                if (npr->precision == (uint32_t)~0)
                        npr->precision = opr->precision;
                rfmt = devaudio_compose_format(npr);
                if ((isctl) || (rfmt == AUDIO_FORMAT_NONE)) {
                        rv = EINVAL;
                        goto err;
                }
        }
        if (reader && CHANGED(npr, opr, buffer_size)) {
                if (isctl) {
                        rv = EINVAL;
                        goto err;
                }
                /* make sure we can support 16-bit stereo samples */
                if ((npr->buffer_size % 4) != 0) {
                        npr->buffer_size = (npr->buffer_size + 3) & ~3;
                }
                /* limit the maximum buffer size somewhat */
                if (npr->buffer_size > 16384) {
                        npr->buffer_size = 16384;
                }
        }

        /* record fields that anyone can modify */
        if (CHANGED(npr, opr, gain)) {
                if (npr->gain > AUDIO_MAX_GAIN) {
                        rv = EINVAL;
                        goto err;
                }
        }

        /*
         * Now apply the changes.
         */
        if (proc->p_writer != NULL) {
                sp = auclnt_output_stream(proc->p_writer);
                npr = &ninfo->play;
                opr = &oinfo->play;

                if (CHANGED(npr, opr, sample_rate)) {
                        if ((rv = auclnt_set_rate(sp, npr->sample_rate)) != 0)
                                goto err;
                }
                if (CHANGED(npr, opr, channels)) {
                        if ((rv = auclnt_set_channels(sp, npr->channels)) != 0)
                                goto err;
                }
                if (pfmt != AUDIO_FORMAT_NONE) {
                        if ((rv = auclnt_set_format(sp, pfmt)) != 0)
                                goto err;
                }
                if (CHANGED(npr, opr, samples)) {
                        auclnt_set_samples(sp, npr->samples);
                }
                if (CHANGED(npr, opr, eof)) {
                        /*
                         * This ugly special case code is required to
                         * prevent problems with realaudio.
                         */
                        if (npr->eof == 0) {
                                devaudio_clear_eof(proc->p_writer);
                        }
                        opr->eof = npr->eof;
                }
                if (CHANGED8(npr, opr, pause)) {
                        if (npr->pause) {
                                auclnt_set_paused(sp);
                        } else {
                                auclnt_clear_paused(sp);

                                /* qenable to start up the playback */
                                qenable(auclnt_get_wq(proc->p_writer));
                        }
                }
                if (CHANGED8(npr, opr, waiting) && (npr->waiting)) {
                        opr->waiting = npr->waiting;
                }
                if (CHANGED8(npr, opr, error)) {
                        auclnt_set_errors(sp, npr->error);
                }
                if (CHANGED(npr, opr, gain)) {
                        auclnt_set_gain(sp, (npr->gain * 100) / AUDIO_MAX_GAIN);
                }
                if (CHANGED8(ninfo, oinfo, output_muted)) {
                        auclnt_set_muted(sp, ninfo->output_muted);
                }
                if (CHANGED(npr, opr, buffer_size)) {
                        /*
                         * No checks on the buffer size are performed
                         * for play side.  The value of the buffer size
                         * is meaningless for play side anyway.
                         */
                        opr->buffer_size = npr->buffer_size;
                }
        } else {
                /* these values are preserved even if /dev/audio not open */
                if (CHANGED(npr, opr, gain)) {
                        opr->gain = npr->gain;
                }
                if (CHANGED8(ninfo, oinfo, output_muted)) {
                        oinfo->output_muted = ninfo->output_muted;
                }
        }

        if (proc->p_reader != NULL) {
                sp = auclnt_input_stream(proc->p_reader);
                npr = &ninfo->record;
                opr = &oinfo->record;

                if (CHANGED(npr, opr, sample_rate)) {
                        if ((rv = auclnt_set_rate(sp, npr->sample_rate)) != 0)
                                goto err;
                }
                if (CHANGED(npr, opr, channels)) {
                        if ((rv = auclnt_set_channels(sp, npr->channels)) != 0)
                                goto err;
                }
                if (rfmt != AUDIO_FORMAT_NONE) {
                        if ((rv = auclnt_set_format(sp, rfmt)) != 0)
                                goto err;
                }
                if (CHANGED(npr, opr, samples)) {
                        auclnt_set_samples(sp, npr->samples);
                }
                if (CHANGED(npr, opr, eof)) {
                        opr->eof = npr->eof;
                }
                if (CHANGED8(npr, opr, pause)) {
                        if (npr->pause) {
                                auclnt_set_paused(sp);
                        } else {
                                auclnt_clear_paused(sp);
                                auclnt_start(sp);
                        }
                }
                if (CHANGED8(npr, opr, waiting) && (npr->waiting)) {
                        opr->waiting = npr->waiting;
                }
                if (CHANGED8(npr, opr, error)) {
                        auclnt_set_errors(sp, npr->error);
                }
                if (CHANGED(npr, opr, buffer_size)) {
                        opr->buffer_size = npr->buffer_size;
                }
                if (CHANGED(npr, opr, gain)) {
                        auclnt_set_gain(sp, (npr->gain * 100) / AUDIO_MAX_GAIN);
                }
        } else {
                /* these values are preserved even if /dev/audio not open */
                if (CHANGED(npr, opr, gain)) {
                        opr->gain = npr->gain;
                }
        }

        devaudio_proc_update(dc->dc_proc);
        bcopy(&dc->dc_proc->p_info, ninfo, sizeof (*ninfo));

        mutex_exit(&dc->dc_dev->d_mx);
        mcopyout(mp, NULL, sizeof (audio_info_t), uaddr, bcont);
        qreply(wq, mp);
        return;

err:
        mutex_exit(&dc->dc_dev->d_mx);
        miocnak(wq, mp, 0, rv);
}

static void
devaudio_ioc_getdev(queue_t *wq, audio_client_t *c, mblk_t *mp)
{
        audio_dev_t     *d = auclnt_get_dev(c);
        mblk_t          *bcont;
        audio_device_t  *a;

        if ((bcont = allocb(sizeof (*a), BPRI_MED)) == NULL) {
                miocnak(wq, mp, 0, ENOMEM);
                return;
        }

        a = (void *)bcont->b_wptr;
        (void) snprintf(a->name, sizeof (a->name),
            "SUNW,%s", auclnt_get_dev_name(d));
        (void) strlcpy(a->config,
            auclnt_get_dev_description(d), sizeof (a->config));
        (void) strlcpy(a->version,
            auclnt_get_dev_version(d),  sizeof (a->version));
        bcont->b_wptr += sizeof (*a);

        mcopyout(mp, NULL, sizeof (*a), NULL, bcont);
        qreply(wq, mp);
}

static int
devaudio_sigpoll(audio_client_t *c, void *arg)
{
        pid_t           pid = (pid_t)(uintptr_t)arg;

        if (auclnt_get_minor_type(c) == AUDIO_MINOR_DEVAUDIOCTL) {
                /* we only need to notify peers in our own process */
                if (auclnt_get_pid(c) == pid) {
                        (void) putctl1(auclnt_get_rq(c), M_PCSIG, SIGPOLL);
                }
        }
        return (AUDIO_WALK_CONTINUE);
}

static void
devaudio_drain(audio_client_t *c)
{
        daclient_t      *dc = auclnt_get_private(c);
        mblk_t          *mplist, *mp;

        mutex_enter(&dc->dc_lock);
        mplist = dc->dc_draining;
        dc->dc_draining = NULL;
        mutex_exit(&dc->dc_lock);

        while ((mp = mplist) != NULL) {
                mplist = mp->b_next;
                mp->b_next = NULL;
                mioc2ack(mp, NULL, 0, 0);
                (void) putq(auclnt_get_rq(c), mp);
        }
}

static void
devaudio_output(audio_client_t *c)
{
        daclient_t      *dc = auclnt_get_private(c);
        daproc_t        *proc = dc->dc_proc;
        uint64_t        tail;
        struct eofcnt   *eof;
        int             eofs = 0;

        tail = auclnt_get_tail(auclnt_output_stream(c));

        /* get more data! (do this early) */
        qenable(auclnt_get_wq(c));

        mutex_enter(&dc->dc_lock);
        while (((eof = list_head(&dc->dc_eofcnt)) != NULL) &&
            (eof->tail <= tail)) {
                list_remove(&dc->dc_eofcnt, eof);
                kmem_free(eof, sizeof (*eof));
                eofs++;
        }
        proc->p_info.play.eof += eofs;
        mutex_exit(&dc->dc_lock);

        if (eofs) {
                auclnt_dev_walk_clients(auclnt_get_dev(c),
                    devaudio_sigpoll, (void *)(uintptr_t)auclnt_get_pid(c));
        }
}

static void *
devaudio_init(audio_dev_t *adev)
{
        dadev_t         *dev;
        unsigned        cap;

        cap = auclnt_get_dev_capab(adev);
        /* if not a play or record device, don't bother initializing it */
        if ((cap & (AUDIO_CLIENT_CAP_PLAY | AUDIO_CLIENT_CAP_RECORD)) == 0) {
                return (NULL);
        }

        dev = kmem_zalloc(sizeof (*dev), KM_SLEEP);
        dev->d_dev = adev;
        mutex_init(&dev->d_mx, NULL, MUTEX_DRIVER, NULL);
        cv_init(&dev->d_cv, NULL, CV_DRIVER, NULL);
        list_create(&dev->d_procs, sizeof (struct daproc),
            offsetof(struct daproc, p_linkage));

        return (dev);
}

static void
devaudio_fini(void *arg)
{
        dadev_t *dev = arg;

        if (dev != NULL) {

                mutex_destroy(&dev->d_mx);
                cv_destroy(&dev->d_cv);
                list_destroy(&dev->d_procs);
                kmem_free(dev, sizeof (*dev));
        }
}

static int
devaudio_open(audio_client_t *c, int oflag)
{
        int     rv;

        if ((rv = auclnt_open(c, oflag)) != 0) {
                return (rv);
        }

        if ((rv = devaudio_proc_hold(c, oflag)) != 0) {
                auclnt_close(c);
                return (rv);
        }

        /* start up the input */
        if (oflag & FREAD) {
                auclnt_start(auclnt_input_stream(c));
        }

        return (0);
}

static int
devaudioctl_open(audio_client_t *c, int oflag)
{
        int     rv;

        _NOTE(ARGUNUSED(oflag));

        oflag &= ~(FWRITE | FREAD);

        if ((rv = auclnt_open(c, 0)) != 0) {
                return (rv);
        }

        if ((rv = devaudio_proc_hold(c, oflag)) != 0) {
                auclnt_close(c);
                return (rv);
        }

        return (0);
}

static void
devaudio_close(audio_client_t *c)
{
        auclnt_stop(auclnt_output_stream(c));
        auclnt_stop(auclnt_input_stream(c));

        auclnt_close(c);
        devaudio_proc_release(c);
}

static void
devaudioctl_close(audio_client_t *c)
{
        auclnt_close(c);
        devaudio_proc_release(c);
}

static void
devaudio_miocdata(audio_client_t *c, mblk_t *mp)
{
        struct copyresp         *csp;
        queue_t                 *wq;

        csp = (void *)mp->b_rptr;
        wq = auclnt_get_wq(c);

        /*
         * If a transfer error occurred, the framework already
         * MIOCNAK'd it.
         */
        if (csp->cp_rval != 0) {
                freemsg(mp);
                return;
        }

        /*
         * If no state, then this is a response to M_COPYOUT, and we
         * are done.  (Audio ioctls just copyout a single structure at
         * completion of work.)
         */
        if (csp->cp_private == NULL) {
                miocack(wq, mp, 0, 0);
                return;
        }

        /* now, call the handler ioctl */
        switch (csp->cp_cmd) {
        case AUDIO_SETINFO:
                devaudio_ioc_setinfo(wq, c, mp);
                break;
        default:
                miocnak(wq, mp, 0, EINVAL);
                break;
        }
}

static void
devaudio_mioctl(audio_client_t *c, mblk_t *mp)
{
        struct iocblk   *iocp = (void *)mp->b_rptr;
        queue_t         *wq = auclnt_get_wq(c);

        /* BSD legacy here: we only support transparent ioctls */
        if (iocp->ioc_count != TRANSPARENT) {
                miocnak(wq, mp, 0, EINVAL);
                return;
        }

        switch (iocp->ioc_cmd) {
        case AUDIO_GETINFO:
                devaudio_ioc_getinfo(wq, c, mp);
                break;

        case AUDIO_SETINFO:
                devaudio_ioc_setinfo(wq, c, mp);
                break;

        case AUDIO_GETDEV:
                devaudio_ioc_getdev(wq, c, mp);
                break;

        case AUDIO_DIAG_LOOPBACK:
                /* we don't support this one */
                miocnak(wq, mp, 0, ENOTTY);
                break;

        case AUDIO_MIXERCTL_GET_MODE:
        case AUDIO_MIXERCTL_SET_MODE:
        case AUDIO_MIXERCTL_GET_CHINFO:
        case AUDIO_MIXERCTL_SET_CHINFO:
        case AUDIO_MIXERCTL_GETINFO:
        case AUDIO_MIXERCTL_SETINFO:
        case AUDIO_GET_NUM_CHS:
        case AUDIO_GET_CH_NUMBER:
        case AUDIO_GET_CH_TYPE:
        case AUDIO_MIXER_SINGLE_OPEN:
        case AUDIO_MIXER_MULTIPLE_OPEN:
        case AUDIO_MIXER_GET_SAMPLE_RATES:
        default:
                miocnak(wq, mp, 0, EINVAL);
                break;
        }
}

static void
devaudioctl_wput(audio_client_t *c, mblk_t *mp)
{
        queue_t         *wq = auclnt_get_wq(c);

        switch (DB_TYPE(mp)) {
        case M_IOCTL:
                /* Drain ioctl needs to be handled on the service queue */
                devaudio_mioctl(c, mp);
                break;

        case M_IOCDATA:
                devaudio_miocdata(c, mp);
                break;

        case M_FLUSH:
                /*
                 * We don't flush the engine.  The reason is that
                 * other streams might be using the engine.  This is
                 * fundamentally no different from the case where the
                 * engine hardware has data buffered in an
                 * inaccessible FIFO.
                 *
                 * Clients that want to ensure no more data is coming
                 * should stop the stream before flushing.
                 */
                if (*mp->b_rptr & FLUSHW) {
                        *mp->b_rptr &= ~FLUSHW;
                }
                if (*mp->b_rptr & FLUSHR) {
                        qreply(wq, mp);
                } else {
                        freemsg(mp);
                }
                break;

        case M_DATA:
                /*
                 * No audio data on control nodes!
                 */

        default:
                freemsg(mp);
                break;
        }
}

static void
devaudio_wput(audio_client_t *c, mblk_t *mp)
{
        queue_t         *wq = auclnt_get_wq(c);

        switch (DB_TYPE(mp)) {
        case M_IOCTL:
                /* Drain ioctl needs to be handled on the service queue */
                if (*(int *)(void *)mp->b_rptr == AUDIO_DRAIN) {
                        (void) putq(wq, mp);
                } else {
                        devaudio_mioctl(c, mp);
                }
                break;

        case M_IOCDATA:
                devaudio_miocdata(c, mp);
                break;

        case M_FLUSH:
                /*
                 * We don't flush the engine.  The reason is that
                 * other streams might be using the engine.  This is
                 * fundamentally no different from the case where the
                 * engine hardware has data buffered in an
                 * inaccessible FIFO.
                 *
                 * Clients that want to ensure no more data is coming
                 * should stop the stream before flushing.
                 */
                if (*mp->b_rptr & FLUSHW) {
                        flushq(wq, FLUSHALL);
                        auclnt_flush(auclnt_output_stream(c));
                        *mp->b_rptr &= ~FLUSHW;
                }
                if (*mp->b_rptr & FLUSHR) {
                        flushq(RD(wq), FLUSHALL);
                        auclnt_flush(auclnt_input_stream(c));
                        qreply(wq, mp);
                } else {
                        freemsg(mp);
                }
                break;

        case M_DATA:
                /*
                 * Defer processing to the queue.  This keeps the data
                 * ordered, and allows the wsrv routine to gather
                 * multiple mblks at once.
                 */
                if (mp->b_cont != NULL) {

                        /*
                         * If we need to pullup, do it here to
                         * simplify the rest of the processing later.
                         * This should rarely (if ever) be necessary.
                         */
                        mblk_t  *nmp;

                        if ((nmp = msgpullup(mp, -1)) == NULL) {
                                freemsg(mp);
                        } else {
                                freemsg(mp);
                                (void) putq(wq, nmp);
                        }
                } else {
                        (void) putq(wq, mp);
                }
                break;

        default:
                freemsg(mp);
                break;
        }
}

static void
devaudio_rsrv(audio_client_t *c)
{
        queue_t         *rq = auclnt_get_rq(c);
        mblk_t          *mp;

        while ((mp = getq(rq)) != NULL) {

                if ((queclass(mp) != QPCTL) && (!canputnext(rq))) {
                        /*
                         * Put it back in the queue so we can apply
                         * backpressure properly.
                         */
                        (void) putbq(rq, mp);
                        return;
                }
                putnext(rq, mp);
        }
}

static void
devaudio_wsrv(audio_client_t *c)
{
        queue_t         *wq = auclnt_get_wq(c);
        daclient_t      *dc = auclnt_get_private(c);
        audio_stream_t  *sp;
        mblk_t          *mp;
        unsigned        framesz;

        sp = auclnt_output_stream(c);

        framesz = auclnt_get_framesz(sp);

        while ((mp = getq(wq)) != NULL) {

                unsigned        count;

                /* got a message */

                /* if its a drain ioctl, we need to process it here */
                if (DB_TYPE(mp) == M_IOCTL) {
                        ASSERT((*(int *)(void *)mp->b_rptr) == AUDIO_DRAIN);
                        mutex_enter(&dc->dc_lock);
                        mp->b_next = dc->dc_draining;
                        dc->dc_draining = mp;
                        mutex_exit(&dc->dc_lock);

                        if (auclnt_start_drain(c) != 0) {
                                devaudio_drain(c);
                        }
                        continue;
                }

                ASSERT(DB_TYPE(mp) == M_DATA);

                /*
                 * Empty mblk require special handling, since they
                 * indicate EOF.  We treat them separate from the main
                 * processing loop.
                 */
                if (MBLKL(mp) == 0) {
                        struct eofcnt   *eof;

                        eof = kmem_zalloc(sizeof (*eof), KM_NOSLEEP);
                        if (eof != NULL) {
                                eof->tail = auclnt_get_head(sp);
                                mutex_enter(&dc->dc_lock);
                                list_insert_tail(&dc->dc_eofcnt, eof);
                                mutex_exit(&dc->dc_lock);
                        }
                        freemsg(mp);
                        continue;
                }

                count = auclnt_produce_data(sp, (caddr_t)mp->b_rptr,
                    MBLKL(mp) / framesz);

                mp->b_rptr += count * framesz;

                if (MBLKL(mp) >= framesz) {
                        (void) putbq(wq, mp);
                        break;
                } else {
                        freemsg(mp);
                }
        }

        /* if the stream isn't running yet, start it up */
        if (!auclnt_is_paused(sp))
                auclnt_start(sp);
}

static struct audio_client_ops devaudio_ops = {
        "sound,audio",
        devaudio_init,
        devaudio_fini,
        devaudio_open,
        devaudio_close,
        NULL,   /* read */
        NULL,   /* write */
        NULL,   /* ioctl */
        NULL,   /* chpoll */
        NULL,   /* mmap */
        devaudio_input,
        devaudio_output,
        devaudio_drain,
        devaudio_wput,
        devaudio_wsrv,
        devaudio_rsrv
};

static struct audio_client_ops devaudioctl_ops = {
        "sound,audioctl",
        NULL,   /* dev_init */
        NULL,   /* dev_fini */
        devaudioctl_open,
        devaudioctl_close,
        NULL,   /* read */
        NULL,   /* write */
        NULL,   /* ioctl */
        NULL,   /* chpoll */
        NULL,   /* mmap */
        NULL,   /* output */
        NULL,   /* input */
        NULL,   /* drain */
        devaudioctl_wput,
        NULL,
        devaudio_rsrv
};

void
auimpl_sun_init(void)
{
        auclnt_register_ops(AUDIO_MINOR_DEVAUDIO, &devaudio_ops);
        auclnt_register_ops(AUDIO_MINOR_DEVAUDIOCTL, &devaudioctl_ops);
}