83 строки
2.0 KiB
C
83 строки
2.0 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* Copyright (c) by Lee Revell <rlrevell@joe-job.com>
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* Clemens Ladisch <clemens@ladisch.de>
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* Routines for control of EMU10K1 chips
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*
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* BUGS:
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* --
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*
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* TODO:
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* --
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*/
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#include <linux/time.h>
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#include <sound/core.h>
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#include <sound/emu10k1.h>
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static int snd_emu10k1_timer_start(struct snd_timer *timer)
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{
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struct snd_emu10k1 *emu;
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unsigned long flags;
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unsigned int delay;
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emu = snd_timer_chip(timer);
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delay = timer->sticks - 1;
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if (delay < 5 ) /* minimum time is 5 ticks */
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delay = 5;
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spin_lock_irqsave(&emu->reg_lock, flags);
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snd_emu10k1_intr_enable(emu, INTE_INTERVALTIMERENB);
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outw(delay & TIMER_RATE_MASK, emu->port + TIMER);
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spin_unlock_irqrestore(&emu->reg_lock, flags);
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return 0;
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}
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static int snd_emu10k1_timer_stop(struct snd_timer *timer)
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{
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struct snd_emu10k1 *emu;
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unsigned long flags;
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emu = snd_timer_chip(timer);
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spin_lock_irqsave(&emu->reg_lock, flags);
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snd_emu10k1_intr_disable(emu, INTE_INTERVALTIMERENB);
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spin_unlock_irqrestore(&emu->reg_lock, flags);
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return 0;
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}
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static int snd_emu10k1_timer_precise_resolution(struct snd_timer *timer,
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unsigned long *num, unsigned long *den)
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{
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*num = 1;
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*den = 48000;
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return 0;
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}
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static const struct snd_timer_hardware snd_emu10k1_timer_hw = {
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.flags = SNDRV_TIMER_HW_AUTO,
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.resolution = 20833, /* 1 sample @ 48KHZ = 20.833...us */
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.ticks = 1024,
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.start = snd_emu10k1_timer_start,
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.stop = snd_emu10k1_timer_stop,
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.precise_resolution = snd_emu10k1_timer_precise_resolution,
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};
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int snd_emu10k1_timer(struct snd_emu10k1 *emu, int device)
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{
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struct snd_timer *timer = NULL;
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struct snd_timer_id tid;
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int err;
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tid.dev_class = SNDRV_TIMER_CLASS_CARD;
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tid.dev_sclass = SNDRV_TIMER_SCLASS_NONE;
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tid.card = emu->card->number;
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tid.device = device;
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tid.subdevice = 0;
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if ((err = snd_timer_new(emu->card, "EMU10K1", &tid, &timer)) >= 0) {
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strcpy(timer->name, "EMU10K1 timer");
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timer->private_data = emu;
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timer->hw = snd_emu10k1_timer_hw;
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}
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emu->timer = timer;
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return err;
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}
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