seq_oss_timer.c

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/*
 * OSS compatible sequencer driver
 *
 * Timer control routines
 *
 * Copyright (C) 1998,99 Takashi Iwai <[email protected]>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
 */

#include "seq_oss_timer.h"
#include "seq_oss_event.h"
#include <sound/seq_oss_legacy.h>
#include <linux/slab.h>

/*
 */
#define MIN_OSS_TEMPO       8
#define MAX_OSS_TEMPO       360
#define MIN_OSS_TIMEBASE    1
#define MAX_OSS_TIMEBASE    1000

/*
 */
static void calc_alsa_tempo(struct seq_oss_timer *timer);
static int send_timer_event(struct seq_oss_devinfo *dp, int type, int value);


/*
 * create and register a new timer.
 * if queue is not started yet, start it.
 */
struct seq_oss_timer *
snd_seq_oss_timer_new(struct seq_oss_devinfo *dp)
{
    struct seq_oss_timer *rec;

    rec = kzalloc(sizeof(*rec), GFP_KERNEL);
    if (rec == NULL)
        return NULL;

    rec->dp = dp;
    rec->cur_tick = 0;
    rec->realtime = 0;
    rec->running = 0;
    rec->oss_tempo = 60;
    rec->oss_timebase = 100;
    calc_alsa_tempo(rec);

    return rec;
}


/*
 * delete timer.
 * if no more timer exists, stop the queue.
 */
void
snd_seq_oss_timer_delete(struct seq_oss_timer *rec)
{
    if (rec) {
        snd_seq_oss_timer_stop(rec);
        kfree(rec);
    }
}


/*
 * process one timing event
 * return 1 : event proceseed -- skip this event
 *        0 : not a timer event -- enqueue this event
 */
int
snd_seq_oss_process_timer_event(struct seq_oss_timer *rec, union evrec *ev)
{
    abstime_t parm = ev->t.time;

    if (ev->t.code == EV_TIMING) {
        switch (ev->t.cmd) {
        case TMR_WAIT_REL:
            parm += rec->cur_tick;
            rec->realtime = 0;
            /* continue to next */
        case TMR_WAIT_ABS:
            if (parm == 0) {
                rec->realtime = 1;
            } else if (parm >= rec->cur_tick) {
                rec->realtime = 0;
                rec->cur_tick = parm;
            }
            return 1;   /* skip this event */
            
        case TMR_START:
            snd_seq_oss_timer_start(rec);
            return 1;

        }
    } else if (ev->s.code == SEQ_WAIT) {
        /* time = from 1 to 3 bytes */
        parm = (ev->echo >> 8) & 0xffffff;
        if (parm > rec->cur_tick) {
            /* set next event time */
            rec->cur_tick = parm;
            rec->realtime = 0;
        }
        return 1;
    }

    return 0;
}


/*
 * convert tempo units
 */
static void
calc_alsa_tempo(struct seq_oss_timer *timer)
{
    timer->tempo = (60 * 1000000) / timer->oss_tempo;
    timer->ppq = timer->oss_timebase;
}


/*
 * dispatch a timer event
 */
static int
send_timer_event(struct seq_oss_devinfo *dp, int type, int value)
{
    struct snd_seq_event ev;

    memset(&ev, 0, sizeof(ev));
    ev.type = type;
    ev.source.client = dp->cseq;
    ev.source.port = 0;
    ev.dest.client = SNDRV_SEQ_CLIENT_SYSTEM;
    ev.dest.port = SNDRV_SEQ_PORT_SYSTEM_TIMER;
    ev.queue = dp->queue;
    ev.data.queue.queue = dp->queue;
    ev.data.queue.param.value = value;
    return snd_seq_kernel_client_dispatch(dp->cseq, &ev, 1, 0);
}

/*
 * set queue tempo and start queue
 */
int
snd_seq_oss_timer_start(struct seq_oss_timer *timer)
{
    struct seq_oss_devinfo *dp = timer->dp;
    struct snd_seq_queue_tempo tmprec;

    if (timer->running)
        snd_seq_oss_timer_stop(timer);

    memset(&tmprec, 0, sizeof(tmprec));
    tmprec.queue = dp->queue;
    tmprec.ppq = timer->ppq;
    tmprec.tempo = timer->tempo;
    snd_seq_set_queue_tempo(dp->cseq, &tmprec);

    send_timer_event(dp, SNDRV_SEQ_EVENT_START, 0);
    timer->running = 1;
    timer->cur_tick = 0;
    return 0;
}


/*
 * stop queue
 */
int
snd_seq_oss_timer_stop(struct seq_oss_timer *timer)
{
    if (! timer->running)
        return 0;
    send_timer_event(timer->dp, SNDRV_SEQ_EVENT_STOP, 0);
    timer->running = 0;
    return 0;
}


/*
 * continue queue
 */
int
snd_seq_oss_timer_continue(struct seq_oss_timer *timer)
{
    if (timer->running)
        return 0;
    send_timer_event(timer->dp, SNDRV_SEQ_EVENT_CONTINUE, 0);
    timer->running = 1;
    return 0;
}


/*
 * change queue tempo
 */
int
snd_seq_oss_timer_tempo(struct seq_oss_timer *timer, int value)
{
    if (value < MIN_OSS_TEMPO)
        value = MIN_OSS_TEMPO;
    else if (value > MAX_OSS_TEMPO)
        value = MAX_OSS_TEMPO;
    timer->oss_tempo = value;
    calc_alsa_tempo(timer);
    if (timer->running)
        send_timer_event(timer->dp, SNDRV_SEQ_EVENT_TEMPO, timer->tempo);
    return 0;
}


/*
 * ioctls
 */
int
snd_seq_oss_timer_ioctl(struct seq_oss_timer *timer, unsigned int cmd, int __user *arg)
{
    int value;

    if (cmd == SNDCTL_SEQ_CTRLRATE) {
        debug_printk(("ctrl rate\n"));
        /* if *arg == 0, just return the current rate */
        if (get_user(value, arg))
            return -EFAULT;
        if (value)
            return -EINVAL;
        value = ((timer->oss_tempo * timer->oss_timebase) + 30) / 60;
        return put_user(value, arg) ? -EFAULT : 0;
    }

    if (timer->dp->seq_mode == SNDRV_SEQ_OSS_MODE_SYNTH)
        return 0;

    switch (cmd) {
    case SNDCTL_TMR_START:
        debug_printk(("timer start\n"));
        return snd_seq_oss_timer_start(timer);
    case SNDCTL_TMR_STOP:
        debug_printk(("timer stop\n"));
        return snd_seq_oss_timer_stop(timer);
    case SNDCTL_TMR_CONTINUE:
        debug_printk(("timer continue\n"));
        return snd_seq_oss_timer_continue(timer);
    case SNDCTL_TMR_TEMPO:
        debug_printk(("timer tempo\n"));
        if (get_user(value, arg))
            return -EFAULT;
        return snd_seq_oss_timer_tempo(timer, value);
    case SNDCTL_TMR_TIMEBASE:
        debug_printk(("timer timebase\n"));
        if (get_user(value, arg))
            return -EFAULT;
        if (value < MIN_OSS_TIMEBASE)
            value = MIN_OSS_TIMEBASE;
        else if (value > MAX_OSS_TIMEBASE)
            value = MAX_OSS_TIMEBASE;
        timer->oss_timebase = value;
        calc_alsa_tempo(timer);
        return 0;

    case SNDCTL_TMR_METRONOME:
    case SNDCTL_TMR_SELECT:
    case SNDCTL_TMR_SOURCE:
        debug_printk(("timer XXX\n"));
        /* not supported */
        return 0;
    }
    return 0;
}