diff options
Diffstat (limited to 'sound/core')
| -rw-r--r-- | sound/core/Kconfig | 21 | ||||
| -rw-r--r-- | sound/core/Makefile | 2 | ||||
| -rw-r--r-- | sound/core/hrtimer.c | 155 | ||||
| -rw-r--r-- | sound/core/seq/seq.c | 4 |
4 files changed, 181 insertions, 1 deletions
diff --git a/sound/core/Kconfig b/sound/core/Kconfig index 66348c92f88d..7bbdda041a99 100644 --- a/sound/core/Kconfig +++ b/sound/core/Kconfig @@ -95,6 +95,26 @@ config SND_SEQUENCER_OSS this will be compiled as a module. The module will be called snd-seq-oss. +config SND_HRTIMER + tristate "HR-timer backend support" + depends on HIGH_RES_TIMERS + select SND_TIMER + help + Say Y here to enable HR-timer backend for ALSA timer. ALSA uses + the hrtimer as a precise timing source. The ALSA sequencer code + also can use this timing source. + + To compile this driver as a module, choose M here: the module + will be called snd-hrtimer. + +config SND_SEQ_HRTIMER_DEFAULT + bool "Use HR-timer as default sequencer timer" + depends on SND_HRTIMER && SND_SEQUENCER + default y + help + Say Y here to use the HR-timer backend as the default sequencer + timer. + config SND_RTCTIMER tristate "RTC Timer support" depends on RTC @@ -114,6 +134,7 @@ config SND_RTCTIMER config SND_SEQ_RTCTIMER_DEFAULT bool "Use RTC as default sequencer timer" depends on SND_RTCTIMER && SND_SEQUENCER + depends on !SND_SEQ_HRTIMER_DEFAULT default y help Say Y here to use the RTC timer as the default sequencer diff --git a/sound/core/Makefile b/sound/core/Makefile index d57125a5687d..4229052e7b91 100644 --- a/sound/core/Makefile +++ b/sound/core/Makefile @@ -17,12 +17,14 @@ snd-page-alloc-$(CONFIG_HAS_DMA) += sgbuf.o snd-rawmidi-objs := rawmidi.o snd-timer-objs := timer.o +snd-hrtimer-objs := hrtimer.o snd-rtctimer-objs := rtctimer.o snd-hwdep-objs := hwdep.o obj-$(CONFIG_SND) += snd.o obj-$(CONFIG_SND_HWDEP) += snd-hwdep.o obj-$(CONFIG_SND_TIMER) += snd-timer.o +obj-$(CONFIG_SND_HRTIMER) += snd-hrtimer.o obj-$(CONFIG_SND_RTCTIMER) += snd-rtctimer.o obj-$(CONFIG_SND_PCM) += snd-pcm.o snd-page-alloc.o obj-$(CONFIG_SND_RAWMIDI) += snd-rawmidi.o diff --git a/sound/core/hrtimer.c b/sound/core/hrtimer.c new file mode 100644 index 000000000000..c1d285921f80 --- /dev/null +++ b/sound/core/hrtimer.c @@ -0,0 +1,155 @@ +/* + * 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/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; +}; + +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; + hrtimer_forward_now(hrt, ns_to_ktime(t->sticks * resolution)); + snd_timer_interrupt(stime->timer, t->sticks); + 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.cb_mode = HRTIMER_CB_IRQSAFE_UNLOCKED; + stime->hrt.function = snd_hrtimer_callback; + 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; + + hrtimer_start(&stime->hrt, ns_to_ktime(t->sticks * resolution), + HRTIMER_MODE_REL); + return 0; +} + +static int snd_hrtimer_stop(struct snd_timer *t) +{ + struct snd_hrtimer *stime = t->private_data; + + hrtimer_cancel(&stime->hrt); + return 0; +} + +static struct snd_timer_hardware hrtimer_hw = { + .flags = SNDRV_TIMER_HW_AUTO, + .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) { + snd_printk(KERN_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); diff --git a/sound/core/seq/seq.c b/sound/core/seq/seq.c index ee0f8405ab35..bf09a5ad1865 100644 --- a/sound/core/seq/seq.c +++ b/sound/core/seq/seq.c @@ -43,7 +43,9 @@ int seq_default_timer_class = SNDRV_TIMER_CLASS_GLOBAL; int seq_default_timer_sclass = SNDRV_TIMER_SCLASS_NONE; int seq_default_timer_card = -1; int seq_default_timer_device = -#ifdef CONFIG_SND_SEQ_RTCTIMER_DEFAULT +#ifdef CONFIG_SND_SEQ_HRTIMER_DEFAULT + SNDRV_TIMER_GLOBAL_HRTIMER +#elif defined(CONFIG_SND_SEQ_RTCTIMER_DEFAULT) SNDRV_TIMER_GLOBAL_RTC #else SNDRV_TIMER_GLOBAL_SYSTEM |