/*
   * 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)
  	  {
  
  		  {
  			  def_tmr.expires = (1) + jiffies;
  			  add_timer(&def_tmr);
  		  }
  
  		  if (tmr_running)
  		    {
  				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
  };