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1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 * Copyright (c) by Lee Revell <rlrevell@joe-job.com>4 * Clemens Ladisch <clemens@ladisch.de>5 * Oswald Buddenhagen <oswald.buddenhagen@gmx.de>6 *7 * Routines for control of EMU10K1 chips8 */9 10#include <linux/time.h>11#include <sound/core.h>12#include <sound/emu10k1.h>13 14static int snd_emu10k1_timer_start(struct snd_timer *timer)15{16 struct snd_emu10k1 *emu;17 unsigned int delay;18 19 emu = snd_timer_chip(timer);20 delay = timer->sticks - 1;21 if (delay < 5 ) /* minimum time is 5 ticks */22 delay = 5;23 snd_emu10k1_intr_enable(emu, INTE_INTERVALTIMERENB);24 outw(delay & TIMER_RATE_MASK, emu->port + TIMER);25 return 0;26}27 28static int snd_emu10k1_timer_stop(struct snd_timer *timer)29{30 struct snd_emu10k1 *emu;31 32 emu = snd_timer_chip(timer);33 snd_emu10k1_intr_disable(emu, INTE_INTERVALTIMERENB);34 return 0;35}36 37static unsigned long snd_emu10k1_timer_c_resolution(struct snd_timer *timer)38{39 struct snd_emu10k1 *emu = snd_timer_chip(timer);40 41 if (emu->card_capabilities->emu_model &&42 emu->emu1010.word_clock == 44100)43 return 22676; // 1 sample @ 44.1 kHz = 22.675736...us44 else45 return 20833; // 1 sample @ 48 kHz = 20.833...us46}47 48static int snd_emu10k1_timer_precise_resolution(struct snd_timer *timer,49 unsigned long *num, unsigned long *den)50{51 struct snd_emu10k1 *emu = snd_timer_chip(timer);52 53 *num = 1;54 if (emu->card_capabilities->emu_model)55 *den = emu->emu1010.word_clock;56 else57 *den = 48000;58 return 0;59}60 61static const struct snd_timer_hardware snd_emu10k1_timer_hw = {62 .flags = SNDRV_TIMER_HW_AUTO,63 .ticks = 1024,64 .start = snd_emu10k1_timer_start,65 .stop = snd_emu10k1_timer_stop,66 .c_resolution = snd_emu10k1_timer_c_resolution,67 .precise_resolution = snd_emu10k1_timer_precise_resolution,68};69 70int snd_emu10k1_timer(struct snd_emu10k1 *emu, int device)71{72 struct snd_timer *timer = NULL;73 struct snd_timer_id tid;74 int err;75 76 tid.dev_class = SNDRV_TIMER_CLASS_CARD;77 tid.dev_sclass = SNDRV_TIMER_SCLASS_NONE;78 tid.card = emu->card->number;79 tid.device = device;80 tid.subdevice = 0;81 err = snd_timer_new(emu->card, "EMU10K1", &tid, &timer);82 if (err >= 0) {83 strcpy(timer->name, "EMU10K1 timer");84 timer->private_data = emu;85 timer->hw = snd_emu10k1_timer_hw;86 }87 emu->timer = timer;88 return err;89}90