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midi/oss_default_timer.c

Default MIDI timer (using system clock)

Description

This file is part of Open Sound System.

Copyright (C) 4Front Technologies 1996-2008.

This this source file is released under GPL v2 license (no other versions). See the COPYING file included in the main directory of this source distribution for the license terms and conditions. 


#include "oss_config.h"
#include "midi_core.h"

typedef struct
{
  unsigned long long start_time;
  timeout_id_t timeout_id;
  oss_midi_wait_callback_t timer_callback;
  void *arg;
} deftmr_timerc_t;

static unsigned long long tick_scale = 1;

static int
deftmr_create_instance (int timer_dev, int driver_dev)
{
  deftmr_timerc_t *timerc;

  if ((timerc = KERNEL_MALLOC (sizeof (*timerc))) == NULL)
    return OSS_ENOMEM;

  memset (timerc, 0, sizeof (*timerc));

  oss_timer_devs[timer_dev]->timerc = timerc;

  return 0;
}

static void
deftmr_free_instance (int timer_dev, int driver_dev)
{
  deftmr_timerc_t *timerc;

  timerc = oss_timer_devs[timer_dev]->timerc;
  untimeout (timerc->timeout_id);

  if (timerc != NULL)
    KERNEL_FREE (timerc);
  oss_timer_devs[timer_dev]->timerc = NULL;
}

static int
deftmr_attach_client (int timer_dev, int mididev)
{
  return 0;
}

static void
deftmr_detach_client (int timer_dev, int mididev)
{
}

static int
deftmr_ioctl (int timer_dev, unsigned int cmd, ioctl_arg arg)
{
  return OSS_EINVAL;
}

static int
deftmr_set_source (int timer_dev, int source)
{
  return source;
}

static int
deftmr_set_tempo (int timer_dev, int tempo)
{
  return tempo;
}

static int
deftmr_set_timebase (int timer_dev, int timebase)
{
  return timebase;
}
static int
deftmr_start (int timer_dev, oss_uint64_t tick)
{
  deftmr_timerc_t *timerc;

  timerc = oss_timer_devs[timer_dev]->timerc;

  if (timerc == NULL)
    {
      cmn_err (CE_WARN, "deftmr_start: timerc==NULL\n");
      return OSS_EIO;
    }

  timerc->start_time = GET_JIFFIES ();
  return 0;
}

static int
deftmr_stop (int timer_dev)
{
  deftmr_timerc_t *timerc;

  timerc = oss_timer_devs[timer_dev]->timerc;
  untimeout (timerc->timeout_id);

  return 0;
}

static int
deftmr_cont (int timer_dev)
{
  return 0;
}

static int
deftmr_wait (int timer_dev, unsigned long long time,
	     oss_midi_wait_callback_t callback, void *arg)
{
  deftmr_timerc_t *timerc;
  unsigned long long t;

  timerc = oss_timer_devs[timer_dev]->timerc;
  untimeout (timerc->timeout_id);

  t = ((oss_uint64_t) time + (tick_scale / 2)) / tick_scale;

  t += timerc->start_time;

  t -= GET_JIFFIES ();

  if (t < 0)
    {
      return 1;
    }

  timerc->timeout_id = timeout (callback, arg, t);

  return 0;
}

static unsigned long long
deftmr_get_current_time (int timer_dev)
{
  unsigned long long t;
  deftmr_timerc_t *timerc;

  timerc = oss_timer_devs[timer_dev]->timerc;

Compute time in system ticks since start of the timer 

  t = GET_JIFFIES ();
  if (t < timerc->start_time)
    return 0;
  t -= timerc->start_time;

  return t * tick_scale;	/* In microseconds */
}

oss_timer_driver_t default_midi_driver = {
  deftmr_create_instance,
  deftmr_free_instance,
  deftmr_attach_client,
  deftmr_detach_client,
  deftmr_ioctl,
  deftmr_wait,
  deftmr_get_current_time,
  deftmr_set_source,
  deftmr_set_tempo,
  deftmr_set_timebase,
  deftmr_start,
  deftmr_stop,
  deftmr_cont
};

void
attach_oss_default_timer (oss_device_t * osdev)
{
  int timer_dev;

  tick_scale = 1000000 / OSS_HZ;
  if ((timer_dev = oss_install_timer (OSS_TIMER_DRIVER_VERSION, "System timer", &default_midi_driver, sizeof (oss_timer_driver_t), 0,	/* Flags */
				      16,	/* max_instances */
				      1000000 / OSS_HZ,	/* Resolution */
				      NULL, osdev)) < 0)
    {
      cmn_err (CE_WARN, "Failed to install default MIDI timer\n");
      return;
    }
}

void
detach_oss_default_timer ()
{
}
Copyright (C) 4Front Technologies, 2007. All rights reserved.

Back to index OSS web site

Copyright (C) 4Front Technologies, 2007. All rights reserved.
Back to index OSS web site