timer.c
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/*
* Copyright (c) by Lee Revell <rlrevell@joe-job.com>
* Clemens Ladisch <clemens@ladisch.de>
* Routines for control of EMU10K1 chips
*
* BUGS:
* --
*
* TODO:
* --
*
* 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 <linux/time.h>
#include <sound/core.h>
#include <sound/emu10k1.h>
static int snd_emu10k1_timer_start(struct snd_timer *timer)
{
struct snd_emu10k1 *emu;
unsigned long flags;
unsigned int delay;
emu = snd_timer_chip(timer);
delay = timer->sticks - 1;
if (delay < 5 ) /* minimum time is 5 ticks */
delay = 5;
spin_lock_irqsave(&emu->reg_lock, flags);
snd_emu10k1_intr_enable(emu, INTE_INTERVALTIMERENB);
outw(delay & TIMER_RATE_MASK, emu->port + TIMER);
spin_unlock_irqrestore(&emu->reg_lock, flags);
return 0;
}
static int snd_emu10k1_timer_stop(struct snd_timer *timer)
{
struct snd_emu10k1 *emu;
unsigned long flags;
emu = snd_timer_chip(timer);
spin_lock_irqsave(&emu->reg_lock, flags);
snd_emu10k1_intr_disable(emu, INTE_INTERVALTIMERENB);
spin_unlock_irqrestore(&emu->reg_lock, flags);
return 0;
}
static int snd_emu10k1_timer_precise_resolution(struct snd_timer *timer,
unsigned long *num, unsigned long *den)
{
*num = 1;
*den = 48000;
return 0;
}
static struct snd_timer_hardware snd_emu10k1_timer_hw = {
.flags = SNDRV_TIMER_HW_AUTO,
.resolution = 20833, /* 1 sample @ 48KHZ = 20.833...us */
.ticks = 1024,
.start = snd_emu10k1_timer_start,
.stop = snd_emu10k1_timer_stop,
.precise_resolution = snd_emu10k1_timer_precise_resolution,
};
int snd_emu10k1_timer(struct snd_emu10k1 *emu, int device)
{
struct snd_timer *timer = NULL;
struct snd_timer_id tid;
int err;
tid.dev_class = SNDRV_TIMER_CLASS_CARD;
tid.dev_sclass = SNDRV_TIMER_SCLASS_NONE;
tid.card = emu->card->number;
tid.device = device;
tid.subdevice = 0;
if ((err = snd_timer_new(emu->card, "EMU10K1", &tid, &timer)) >= 0) {
strcpy(timer->name, "EMU10K1 timer");
timer->private_data = emu;
timer->hw = snd_emu10k1_timer_hw;
}
emu->timer = timer;
return err;
}