1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
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 chips
8 */
9
10 #include <linux/time.h>
11 #include <sound/core.h>
12 #include <sound/emu10k1.h>
13
14 static 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
28 static 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
37 static 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...us
44 else
45 return 20833; // 1 sample @ 48 kHz = 20.833...us
46 }
47
48 static 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 else
57 *den = 48000;
58 return 0;
59 }
60
61 static 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
70 int 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
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