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 *  Routines for control of EMU10K1 chips
6 *
7 *  BUGS:
8 *    --
9 *
10 *  TODO:
11 *    --
12 */
13
14#include <linux/time.h>
15#include <sound/core.h>
16#include <sound/emu10k1.h>
17
18static int snd_emu10k1_timer_start(struct snd_timer *timer)
19{
20	struct snd_emu10k1 *emu;
21	unsigned long flags;
22	unsigned int delay;
23
24	emu = snd_timer_chip(timer);
25	delay = timer->sticks - 1;
26	if (delay < 5 ) /* minimum time is 5 ticks */
27		delay = 5;
28	spin_lock_irqsave(&emu->reg_lock, flags);
29	snd_emu10k1_intr_enable(emu, INTE_INTERVALTIMERENB);
30	outw(delay & TIMER_RATE_MASK, emu->port + TIMER);
31	spin_unlock_irqrestore(&emu->reg_lock, flags);
32	return 0;
33}
34
35static int snd_emu10k1_timer_stop(struct snd_timer *timer)
36{
37	struct snd_emu10k1 *emu;
38	unsigned long flags;
39
40	emu = snd_timer_chip(timer);
41	spin_lock_irqsave(&emu->reg_lock, flags);
42	snd_emu10k1_intr_disable(emu, INTE_INTERVALTIMERENB);
43	spin_unlock_irqrestore(&emu->reg_lock, flags);
44	return 0;
45}
46
47static int snd_emu10k1_timer_precise_resolution(struct snd_timer *timer,
48					       unsigned long *num, unsigned long *den)
49{
50	*num = 1;
51	*den = 48000;
52	return 0;
53}
54
55static const struct snd_timer_hardware snd_emu10k1_timer_hw = {
56	.flags = SNDRV_TIMER_HW_AUTO,
57	.resolution = 20833, /* 1 sample @ 48KHZ = 20.833...us */
58	.ticks = 1024,
59	.start = snd_emu10k1_timer_start,
60	.stop = snd_emu10k1_timer_stop,
61	.precise_resolution = snd_emu10k1_timer_precise_resolution,
62};
63
64int snd_emu10k1_timer(struct snd_emu10k1 *emu, int device)
65{
66	struct snd_timer *timer = NULL;
67	struct snd_timer_id tid;
68	int err;
69
70	tid.dev_class = SNDRV_TIMER_CLASS_CARD;
71	tid.dev_sclass = SNDRV_TIMER_SCLASS_NONE;
72	tid.card = emu->card->number;
73	tid.device = device;
74	tid.subdevice = 0;
75	if ((err = snd_timer_new(emu->card, "EMU10K1", &tid, &timer)) >= 0) {
76		strcpy(timer->name, "EMU10K1 timer");
77		timer->private_data = emu;
78		timer->hw = snd_emu10k1_timer_hw;
79	}
80	emu->timer = timer;
81	return err;
82}
83