root/sound/pci/emu10k1/timer.c

DEFINITIONS

1. snd_emu10k1_timer_start
2. snd_emu10k1_timer_stop
3. snd_emu10k1_timer_precise_resolution
4. snd_emu10k1_timer

/*
 *  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 __devinit 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;
}