cf74dcf351
Use the standard pr_xxx() helpers instead of home-baked snd_print*(). Signed-off-by: Takashi Iwai <tiwai@suse.de>
166 lines
4 KiB
C
166 lines
4 KiB
C
/*
|
|
* ALSA timer back-end using hrtimer
|
|
* Copyright (C) 2008 Takashi Iwai
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License as published by
|
|
* the Free Software Foundation; either version 2 of the License, or
|
|
* (at your option) any later version.
|
|
*
|
|
* This program is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
* GNU General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License
|
|
* along with this program; if not, write to the Free Software
|
|
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
|
|
*
|
|
*/
|
|
|
|
#include <linux/init.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/module.h>
|
|
#include <linux/moduleparam.h>
|
|
#include <linux/hrtimer.h>
|
|
#include <sound/core.h>
|
|
#include <sound/timer.h>
|
|
|
|
MODULE_AUTHOR("Takashi Iwai <tiwai@suse.de>");
|
|
MODULE_DESCRIPTION("ALSA hrtimer backend");
|
|
MODULE_LICENSE("GPL");
|
|
|
|
MODULE_ALIAS("snd-timer-" __stringify(SNDRV_TIMER_GLOBAL_HRTIMER));
|
|
|
|
#define NANO_SEC 1000000000UL /* 10^9 in sec */
|
|
static unsigned int resolution;
|
|
|
|
struct snd_hrtimer {
|
|
struct snd_timer *timer;
|
|
struct hrtimer hrt;
|
|
atomic_t running;
|
|
};
|
|
|
|
static enum hrtimer_restart snd_hrtimer_callback(struct hrtimer *hrt)
|
|
{
|
|
struct snd_hrtimer *stime = container_of(hrt, struct snd_hrtimer, hrt);
|
|
struct snd_timer *t = stime->timer;
|
|
unsigned long oruns;
|
|
|
|
if (!atomic_read(&stime->running))
|
|
return HRTIMER_NORESTART;
|
|
|
|
oruns = hrtimer_forward_now(hrt, ns_to_ktime(t->sticks * resolution));
|
|
snd_timer_interrupt(stime->timer, t->sticks * oruns);
|
|
|
|
if (!atomic_read(&stime->running))
|
|
return HRTIMER_NORESTART;
|
|
return HRTIMER_RESTART;
|
|
}
|
|
|
|
static int snd_hrtimer_open(struct snd_timer *t)
|
|
{
|
|
struct snd_hrtimer *stime;
|
|
|
|
stime = kmalloc(sizeof(*stime), GFP_KERNEL);
|
|
if (!stime)
|
|
return -ENOMEM;
|
|
hrtimer_init(&stime->hrt, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
|
|
stime->timer = t;
|
|
stime->hrt.function = snd_hrtimer_callback;
|
|
atomic_set(&stime->running, 0);
|
|
t->private_data = stime;
|
|
return 0;
|
|
}
|
|
|
|
static int snd_hrtimer_close(struct snd_timer *t)
|
|
{
|
|
struct snd_hrtimer *stime = t->private_data;
|
|
|
|
if (stime) {
|
|
hrtimer_cancel(&stime->hrt);
|
|
kfree(stime);
|
|
t->private_data = NULL;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static int snd_hrtimer_start(struct snd_timer *t)
|
|
{
|
|
struct snd_hrtimer *stime = t->private_data;
|
|
|
|
atomic_set(&stime->running, 0);
|
|
hrtimer_cancel(&stime->hrt);
|
|
hrtimer_start(&stime->hrt, ns_to_ktime(t->sticks * resolution),
|
|
HRTIMER_MODE_REL);
|
|
atomic_set(&stime->running, 1);
|
|
return 0;
|
|
}
|
|
|
|
static int snd_hrtimer_stop(struct snd_timer *t)
|
|
{
|
|
struct snd_hrtimer *stime = t->private_data;
|
|
atomic_set(&stime->running, 0);
|
|
return 0;
|
|
}
|
|
|
|
static struct snd_timer_hardware hrtimer_hw = {
|
|
.flags = SNDRV_TIMER_HW_AUTO | SNDRV_TIMER_HW_TASKLET,
|
|
.open = snd_hrtimer_open,
|
|
.close = snd_hrtimer_close,
|
|
.start = snd_hrtimer_start,
|
|
.stop = snd_hrtimer_stop,
|
|
};
|
|
|
|
/*
|
|
* entry functions
|
|
*/
|
|
|
|
static struct snd_timer *mytimer;
|
|
|
|
static int __init snd_hrtimer_init(void)
|
|
{
|
|
struct snd_timer *timer;
|
|
struct timespec tp;
|
|
int err;
|
|
|
|
hrtimer_get_res(CLOCK_MONOTONIC, &tp);
|
|
if (tp.tv_sec > 0 || !tp.tv_nsec) {
|
|
pr_err("snd-hrtimer: Invalid resolution %u.%09u",
|
|
(unsigned)tp.tv_sec, (unsigned)tp.tv_nsec);
|
|
return -EINVAL;
|
|
}
|
|
resolution = tp.tv_nsec;
|
|
|
|
/* Create a new timer and set up the fields */
|
|
err = snd_timer_global_new("hrtimer", SNDRV_TIMER_GLOBAL_HRTIMER,
|
|
&timer);
|
|
if (err < 0)
|
|
return err;
|
|
|
|
timer->module = THIS_MODULE;
|
|
strcpy(timer->name, "HR timer");
|
|
timer->hw = hrtimer_hw;
|
|
timer->hw.resolution = resolution;
|
|
timer->hw.ticks = NANO_SEC / resolution;
|
|
|
|
err = snd_timer_global_register(timer);
|
|
if (err < 0) {
|
|
snd_timer_global_free(timer);
|
|
return err;
|
|
}
|
|
mytimer = timer; /* remember this */
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void __exit snd_hrtimer_exit(void)
|
|
{
|
|
if (mytimer) {
|
|
snd_timer_global_free(mytimer);
|
|
mytimer = NULL;
|
|
}
|
|
}
|
|
|
|
module_init(snd_hrtimer_init);
|
|
module_exit(snd_hrtimer_exit);
|