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 <sound/driver.h>
29#include <linux/time.h>
30#include <sound/core.h>
31#include <sound/emu10k1.h>
32
33static int snd_emu10k1_timer_start(struct snd_timer *timer)
34{
35	struct snd_emu10k1 *emu;
36	unsigned long flags;
37	unsigned int delay;
38
39	emu = snd_timer_chip(timer);
40	delay = timer->sticks - 1;
41	if (delay < 5 ) /* minimum time is 5 ticks */
42		delay = 5;
43	spin_lock_irqsave(&emu->reg_lock, flags);
44	snd_emu10k1_intr_enable(emu, INTE_INTERVALTIMERENB);
45	outw(delay & TIMER_RATE_MASK, emu->port + TIMER);
46	spin_unlock_irqrestore(&emu->reg_lock, flags);
47	return 0;
48}
49
50static int snd_emu10k1_timer_stop(struct snd_timer *timer)
51{
52	struct snd_emu10k1 *emu;
53	unsigned long flags;
54
55	emu = snd_timer_chip(timer);
56	spin_lock_irqsave(&emu->reg_lock, flags);
57	snd_emu10k1_intr_disable(emu, INTE_INTERVALTIMERENB);
58	spin_unlock_irqrestore(&emu->reg_lock, flags);
59	return 0;
60}
61
62static int snd_emu10k1_timer_precise_resolution(struct snd_timer *timer,
63					       unsigned long *num, unsigned long *den)
64{
65	*num = 1;
66	*den = 48000;
67	return 0;
68}
69
70static struct snd_timer_hardware snd_emu10k1_timer_hw = {
71	.flags = SNDRV_TIMER_HW_AUTO,
72	.resolution = 20833, /* 1 sample @ 48KHZ = 20.833...us */
73	.ticks = 1024,
74	.start = snd_emu10k1_timer_start,
75	.stop = snd_emu10k1_timer_stop,
76	.precise_resolution = snd_emu10k1_timer_precise_resolution,
77};
78
79int __devinit snd_emu10k1_timer(struct snd_emu10k1 *emu, int device)
80{
81	struct snd_timer *timer = NULL;
82	struct snd_timer_id tid;
83	int err;
84
85	tid.dev_class = SNDRV_TIMER_CLASS_CARD;
86	tid.dev_sclass = SNDRV_TIMER_SCLASS_NONE;
87	tid.card = emu->card->number;
88	tid.device = device;
89	tid.subdevice = 0;
90	if ((err = snd_timer_new(emu->card, "EMU10K1", &tid, &timer)) >= 0) {
91		strcpy(timer->name, "EMU10K1 timer");
92		timer->private_data = emu;
93		timer->hw = snd_emu10k1_timer_hw;
94	}
95	emu->timer = timer;
96	return err;
97}
98