1/*
2 *  Copyright (c) by Lee Revell <rlrevell@joe-job.com>
3 *                   Clemens Ladisch <clemens@ladisch.de>
4 *  Routines for control of EMU10K1 chips
5 *
6 *  BUGS:
7 *    --
8 *
9 *  TODO:
10 *    --
11 *
12 *   This program is free software; you can redistribute it and/or modify
13 *   it under the terms of the GNU General Public License as published by
14 *   the Free Software Foundation; either version 2 of the License, or
15 *   (at your option) any later version.
16 *
17 *   This program is distributed in the hope that it will be useful,
18 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
19 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
20 *   GNU General Public License for more details.
21 *
22 *   You should have received a copy of the GNU General Public License
23 *   along with this program; if not, write to the Free Software
24 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
25 *
26 */
27
28#include <linux/time.h>
29#include <sound/core.h>
30#include <sound/emu10k1.h>
31
32static int snd_emu10k1_timer_start(struct snd_timer *timer)
33{
34	struct snd_emu10k1 *emu;
35	unsigned long flags;
36	unsigned int delay;
37
38	emu = snd_timer_chip(timer);
39	delay = timer->sticks - 1;
40	if (delay < 5 ) /* minimum time is 5 ticks */
41		delay = 5;
42	spin_lock_irqsave(&emu->reg_lock, flags);
43	snd_emu10k1_intr_enable(emu, INTE_INTERVALTIMERENB);
44	outw(delay & TIMER_RATE_MASK, emu->port + TIMER);
45	spin_unlock_irqrestore(&emu->reg_lock, flags);
46	return 0;
47}
48
49static int snd_emu10k1_timer_stop(struct snd_timer *timer)
50{
51	struct snd_emu10k1 *emu;
52	unsigned long flags;
53
54	emu = snd_timer_chip(timer);
55	spin_lock_irqsave(&emu->reg_lock, flags);
56	snd_emu10k1_intr_disable(emu, INTE_INTERVALTIMERENB);
57	spin_unlock_irqrestore(&emu->reg_lock, flags);
58	return 0;
59}
60
61static int snd_emu10k1_timer_precise_resolution(struct snd_timer *timer,
62					       unsigned long *num, unsigned long *den)
63{
64	*num = 1;
65	*den = 48000;
66	return 0;
67}
68
69static struct snd_timer_hardware snd_emu10k1_timer_hw = {
70	.flags = SNDRV_TIMER_HW_AUTO,
71	.resolution = 20833, /* 1 sample @ 48KHZ = 20.833...us */
72	.ticks = 1024,
73	.start = snd_emu10k1_timer_start,
74	.stop = snd_emu10k1_timer_stop,
75	.precise_resolution = snd_emu10k1_timer_precise_resolution,
76};
77
78int snd_emu10k1_timer(struct snd_emu10k1 *emu, int device)
79{
80	struct snd_timer *timer = NULL;
81	struct snd_timer_id tid;
82	int err;
83
84	tid.dev_class = SNDRV_TIMER_CLASS_CARD;
85	tid.dev_sclass = SNDRV_TIMER_SCLASS_NONE;
86	tid.card = emu->card->number;
87	tid.device = device;
88	tid.subdevice = 0;
89	if ((err = snd_timer_new(emu->card, "EMU10K1", &tid, &timer)) >= 0) {
90		strcpy(timer->name, "EMU10K1 timer");
91		timer->private_data = emu;
92		timer->hw = snd_emu10k1_timer_hw;
93	}
94	emu->timer = timer;
95	return err;
96}
97