/*
 * sound/oss/sys_timer.c
 *
 * The default timer for the Level 2 sequencer interface
 * Uses the (1/HZ sec) timer of kernel.
 */
/*
 * Copyright (C) by Hannu Savolainen 1993-1997
 *
 * OSS/Free for Linux is distributed under the GNU GENERAL PUBLIC LICENSE (GPL)
 * Version 2 (June 1991). See the "COPYING" file distributed with this software
 * for more info.
 */
/*
 * Thomas Sailer   : ioctl code reworked (vmalloc/vfree removed)
 * Andrew Veliath  : adapted tmr2ticks from level 1 sequencer (avoid overflow)
 */
#include <linux/spinlock.h>
#include "sound_config.h"

static volatile int opened, tmr_running;
static volatile time_t tmr_offs, tmr_ctr;
static volatile unsigned long ticks_offs;
static volatile int curr_tempo, curr_timebase;
static volatile unsigned long curr_ticks;
static volatile unsigned long next_event_time;
static unsigned long prev_event_time;

static void     poll_def_tmr(unsigned long dummy);
static DEFINE_SPINLOCK(lock);
static DEFINE_TIMER(def_tmr, poll_def_tmr, 0, 0);

static unsigned long
tmr2ticks(int tmr_value)
{
        /*
         *    Convert timer ticks to MIDI ticks
         */

        unsigned long tmp;
        unsigned long scale;

        /* tmr_value (ticks per sec) *
           1000000 (usecs per sec) / HZ (ticks per sec) -=> usecs */
        tmp = tmr_value * (1000000 / HZ);
        scale = (60 * 1000000) / (curr_tempo * curr_timebase);  /* usecs per MIDI tick */
        return (tmp + scale / 2) / scale;
}

static void
poll_def_tmr(unsigned long dummy)
{
        if (!opened)
                return;
        def_tmr.expires = (1) + jiffies;
        add_timer(&def_tmr);

        if (!tmr_running)
                return;

        spin_lock(&lock);
        tmr_ctr++;
        curr_ticks = ticks_offs + tmr2ticks(tmr_ctr);

        if (curr_ticks >= next_event_time) {
                next_event_time = (unsigned long) -1;
                sequencer_timer(0);
        }

        spin_unlock(&lock);
}

static void
tmr_reset(void)
{
        unsigned long   flags;

        spin_lock_irqsave(&lock,flags);
        tmr_offs = 0;
        ticks_offs = 0;
        tmr_ctr = 0;
        next_event_time = (unsigned long) -1;
        prev_event_time = 0;
        curr_ticks = 0;
        spin_unlock_irqrestore(&lock,flags);
}

static int
def_tmr_open(int dev, int mode)
{
        if (opened)
                return -EBUSY;

        tmr_reset();
        curr_tempo = 60;
        curr_timebase = 100;
        opened = 1;
        {
                def_tmr.expires = (1) + jiffies;
                add_timer(&def_tmr);
        }

        return 0;
}

static void
def_tmr_close(int dev)
{
        opened = tmr_running = 0;
        del_timer(&def_tmr);
}

static int
def_tmr_event(int dev, unsigned char *event)
{
        unsigned char   cmd = event[1];
        unsigned long   parm = *(int *) &event[4];

        switch (cmd)
          {
          case TMR_WAIT_REL:
                  parm += prev_event_time;
          case TMR_WAIT_ABS:
                  if (parm > 0)
                    {
                            long            time;

                            if (parm <= curr_ticks)     /* It's the time */
                                    return TIMER_NOT_ARMED;

                            time = parm;
                            next_event_time = prev_event_time = time;

                            return TIMER_ARMED;
                    }
                  break;

          case TMR_START:
                  tmr_reset();
                  tmr_running = 1;
                  break;

          case TMR_STOP:
                  tmr_running = 0;
                  break;

          case TMR_CONTINUE:
                  tmr_running = 1;
                  break;

          case TMR_TEMPO:
                  if (parm)
                    {
                            if (parm < 8)
                                    parm = 8;
                            if (parm > 360)
                                    parm = 360;
                            tmr_offs = tmr_ctr;
                            ticks_offs += tmr2ticks(tmr_ctr);
                            tmr_ctr = 0;
                            curr_tempo = parm;
                    }
                  break;

          case TMR_ECHO:
                  seq_copy_to_input(event, 8);
                  break;

          default:;
          }

        return TIMER_NOT_ARMED;
}

static unsigned long
def_tmr_get_time(int dev)
{
        if (!opened)
                return 0;

        return curr_ticks;
}

/* same as sound_timer.c:timer_ioctl!? */
static int def_tmr_ioctl(int dev, unsigned int cmd, void __user *arg)
{
        int __user *p = arg;
        int val;

        switch (cmd) {
        case SNDCTL_TMR_SOURCE:
                return __put_user(TMR_INTERNAL, p);

        case SNDCTL_TMR_START:
                tmr_reset();
                tmr_running = 1;
                return 0;

        case SNDCTL_TMR_STOP:
                tmr_running = 0;
                return 0;

        case SNDCTL_TMR_CONTINUE:
                tmr_running = 1;
                return 0;

        case SNDCTL_TMR_TIMEBASE:
                if (__get_user(val, p))
                        return -EFAULT;
                if (val) {
                        if (val < 1)
                                val = 1;
                        if (val > 1000)
                                val = 1000;
                        curr_timebase = val;
                }
                return __put_user(curr_timebase, p);

        case SNDCTL_TMR_TEMPO:
                if (__get_user(val, p))
                        return -EFAULT;
                if (val) {
                        if (val < 8)
                                val = 8;
                        if (val > 250)
                                val = 250;
                        tmr_offs = tmr_ctr;
                        ticks_offs += tmr2ticks(tmr_ctr);
                        tmr_ctr = 0;
                        curr_tempo = val;
                        reprogram_timer();
                }
                return __put_user(curr_tempo, p);

        case SNDCTL_SEQ_CTRLRATE:
                if (__get_user(val, p))
                        return -EFAULT;
                if (val != 0)   /* Can't change */
                        return -EINVAL;
                val = ((curr_tempo * curr_timebase) + 30) / 60;
                return __put_user(val, p);
                
        case SNDCTL_SEQ_GETTIME:
                return __put_user(curr_ticks, p);
                
        case SNDCTL_TMR_METRONOME:
                /* NOP */
                break;
                
        default:;
        }
        return -EINVAL;
}

static void
def_tmr_arm(int dev, long time)
{
        if (time < 0)
                time = curr_ticks + 1;
        else if (time <= curr_ticks)    /* It's the time */
                return;

        next_event_time = prev_event_time = time;

        return;
}

struct sound_timer_operations default_sound_timer =
{
        .owner          = THIS_MODULE,
        .info           = {"System clock", 0},
        .priority       = 0,    /* Priority */
        .devlink        = 0,    /* Local device link */
        .open           = def_tmr_open,
        .close          = def_tmr_close,
        .event          = def_tmr_event,
        .get_time       = def_tmr_get_time,
        .ioctl          = def_tmr_ioctl,
        .arm_timer      = def_tmr_arm
};