/*
 * OSS compatible sequencer driver
 *
 * Timer control routines
 *
 * Copyright (C) 1998,99 Takashi Iwai <tiwai@suse.de>
 *
 * 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) {
                /* 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:
                return snd_seq_oss_timer_start(timer);
        case SNDCTL_TMR_STOP:
                return snd_seq_oss_timer_stop(timer);
        case SNDCTL_TMR_CONTINUE:
                return snd_seq_oss_timer_continue(timer);
        case SNDCTL_TMR_TEMPO:
                if (get_user(value, arg))
                        return -EFAULT;
                return snd_seq_oss_timer_tempo(timer, value);
        case SNDCTL_TMR_TIMEBASE:
                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:
                /* not supported */
                return 0;
        }
        return 0;
}