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 
snd_emu10k1_timer_start(struct snd_timer * timer)18 static 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 
snd_emu10k1_timer_stop(struct snd_timer * timer)35 static 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 
snd_emu10k1_timer_precise_resolution(struct snd_timer * timer,unsigned long * num,unsigned long * den)47 static 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 
55 static 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 
snd_emu10k1_timer(struct snd_emu10k1 * emu,int device)64 int 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 	err = snd_timer_new(emu->card, "EMU10K1", &tid, &timer);
76 	if (err >= 0) {
77 		strcpy(timer->name, "EMU10K1 timer");
78 		timer->private_data = emu;
79 		timer->hw = snd_emu10k1_timer_hw;
80 	}
81 	emu->timer = timer;
82 	return err;
83 }
84