linux/sound/pci/ctxfi/cttimer.c
Julia Lawall 5305239312 ALSA: constify ct_timer_ops structures
The ct_timer_ops structures are never modified, so declare them as const.

Done with the help of Coccinelle.

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2016-04-09 10:58:04 +02:00

444 lines
11 KiB
C

/*
* PCM timer handling on ctxfi
*
* This source file is released under GPL v2 license (no other versions).
* See the COPYING file included in the main directory of this source
* distribution for the license terms and conditions.
*/
#include <linux/slab.h>
#include <linux/math64.h>
#include <linux/moduleparam.h>
#include <sound/core.h>
#include <sound/pcm.h>
#include "ctatc.h"
#include "cthardware.h"
#include "cttimer.h"
static bool use_system_timer;
MODULE_PARM_DESC(use_system_timer, "Force to use system-timer");
module_param(use_system_timer, bool, S_IRUGO);
struct ct_timer_ops {
void (*init)(struct ct_timer_instance *);
void (*prepare)(struct ct_timer_instance *);
void (*start)(struct ct_timer_instance *);
void (*stop)(struct ct_timer_instance *);
void (*free_instance)(struct ct_timer_instance *);
void (*interrupt)(struct ct_timer *);
void (*free_global)(struct ct_timer *);
};
/* timer instance -- assigned to each PCM stream */
struct ct_timer_instance {
spinlock_t lock;
struct ct_timer *timer_base;
struct ct_atc_pcm *apcm;
struct snd_pcm_substream *substream;
struct timer_list timer;
struct list_head instance_list;
struct list_head running_list;
unsigned int position;
unsigned int frag_count;
unsigned int running:1;
unsigned int need_update:1;
};
/* timer instance manager */
struct ct_timer {
spinlock_t lock; /* global timer lock (for xfitimer) */
spinlock_t list_lock; /* lock for instance list */
struct ct_atc *atc;
const struct ct_timer_ops *ops;
struct list_head instance_head;
struct list_head running_head;
unsigned int wc; /* current wallclock */
unsigned int irq_handling:1; /* in IRQ handling */
unsigned int reprogram:1; /* need to reprogram the internval */
unsigned int running:1; /* global timer running */
};
/*
* system-timer-based updates
*/
static void ct_systimer_callback(unsigned long data)
{
struct ct_timer_instance *ti = (struct ct_timer_instance *)data;
struct snd_pcm_substream *substream = ti->substream;
struct snd_pcm_runtime *runtime = substream->runtime;
struct ct_atc_pcm *apcm = ti->apcm;
unsigned int period_size = runtime->period_size;
unsigned int buffer_size = runtime->buffer_size;
unsigned long flags;
unsigned int position, dist, interval;
position = substream->ops->pointer(substream);
dist = (position + buffer_size - ti->position) % buffer_size;
if (dist >= period_size ||
position / period_size != ti->position / period_size) {
apcm->interrupt(apcm);
ti->position = position;
}
/* Add extra HZ*5/1000 to avoid overrun issue when recording
* at 8kHz in 8-bit format or at 88kHz in 24-bit format. */
interval = ((period_size - (position % period_size))
* HZ + (runtime->rate - 1)) / runtime->rate + HZ * 5 / 1000;
spin_lock_irqsave(&ti->lock, flags);
if (ti->running)
mod_timer(&ti->timer, jiffies + interval);
spin_unlock_irqrestore(&ti->lock, flags);
}
static void ct_systimer_init(struct ct_timer_instance *ti)
{
setup_timer(&ti->timer, ct_systimer_callback,
(unsigned long)ti);
}
static void ct_systimer_start(struct ct_timer_instance *ti)
{
struct snd_pcm_runtime *runtime = ti->substream->runtime;
unsigned long flags;
spin_lock_irqsave(&ti->lock, flags);
ti->running = 1;
mod_timer(&ti->timer,
jiffies + (runtime->period_size * HZ +
(runtime->rate - 1)) / runtime->rate);
spin_unlock_irqrestore(&ti->lock, flags);
}
static void ct_systimer_stop(struct ct_timer_instance *ti)
{
unsigned long flags;
spin_lock_irqsave(&ti->lock, flags);
ti->running = 0;
del_timer(&ti->timer);
spin_unlock_irqrestore(&ti->lock, flags);
}
static void ct_systimer_prepare(struct ct_timer_instance *ti)
{
ct_systimer_stop(ti);
try_to_del_timer_sync(&ti->timer);
}
#define ct_systimer_free ct_systimer_prepare
static const struct ct_timer_ops ct_systimer_ops = {
.init = ct_systimer_init,
.free_instance = ct_systimer_free,
.prepare = ct_systimer_prepare,
.start = ct_systimer_start,
.stop = ct_systimer_stop,
};
/*
* Handling multiple streams using a global emu20k1 timer irq
*/
#define CT_TIMER_FREQ 48000
#define MIN_TICKS 1
#define MAX_TICKS ((1 << 13) - 1)
static void ct_xfitimer_irq_rearm(struct ct_timer *atimer, int ticks)
{
struct hw *hw = atimer->atc->hw;
if (ticks > MAX_TICKS)
ticks = MAX_TICKS;
hw->set_timer_tick(hw, ticks);
if (!atimer->running)
hw->set_timer_irq(hw, 1);
atimer->running = 1;
}
static void ct_xfitimer_irq_stop(struct ct_timer *atimer)
{
if (atimer->running) {
struct hw *hw = atimer->atc->hw;
hw->set_timer_irq(hw, 0);
hw->set_timer_tick(hw, 0);
atimer->running = 0;
}
}
static inline unsigned int ct_xfitimer_get_wc(struct ct_timer *atimer)
{
struct hw *hw = atimer->atc->hw;
return hw->get_wc(hw);
}
/*
* reprogram the timer interval;
* checks the running instance list and determines the next timer interval.
* also updates the each stream position, returns the number of streams
* to call snd_pcm_period_elapsed() appropriately
*
* call this inside the lock and irq disabled
*/
static int ct_xfitimer_reprogram(struct ct_timer *atimer, int can_update)
{
struct ct_timer_instance *ti;
unsigned int min_intr = (unsigned int)-1;
int updates = 0;
unsigned int wc, diff;
if (list_empty(&atimer->running_head)) {
ct_xfitimer_irq_stop(atimer);
atimer->reprogram = 0; /* clear flag */
return 0;
}
wc = ct_xfitimer_get_wc(atimer);
diff = wc - atimer->wc;
atimer->wc = wc;
list_for_each_entry(ti, &atimer->running_head, running_list) {
if (ti->frag_count > diff)
ti->frag_count -= diff;
else {
unsigned int pos;
unsigned int period_size, rate;
period_size = ti->substream->runtime->period_size;
rate = ti->substream->runtime->rate;
pos = ti->substream->ops->pointer(ti->substream);
if (pos / period_size != ti->position / period_size) {
ti->need_update = 1;
ti->position = pos;
updates++;
}
pos %= period_size;
pos = period_size - pos;
ti->frag_count = div_u64((u64)pos * CT_TIMER_FREQ +
rate - 1, rate);
}
if (ti->need_update && !can_update)
min_intr = 0; /* pending to the next irq */
if (ti->frag_count < min_intr)
min_intr = ti->frag_count;
}
if (min_intr < MIN_TICKS)
min_intr = MIN_TICKS;
ct_xfitimer_irq_rearm(atimer, min_intr);
atimer->reprogram = 0; /* clear flag */
return updates;
}
/* look through the instance list and call period_elapsed if needed */
static void ct_xfitimer_check_period(struct ct_timer *atimer)
{
struct ct_timer_instance *ti;
unsigned long flags;
spin_lock_irqsave(&atimer->list_lock, flags);
list_for_each_entry(ti, &atimer->instance_head, instance_list) {
if (ti->running && ti->need_update) {
ti->need_update = 0;
ti->apcm->interrupt(ti->apcm);
}
}
spin_unlock_irqrestore(&atimer->list_lock, flags);
}
/* Handle timer-interrupt */
static void ct_xfitimer_callback(struct ct_timer *atimer)
{
int update;
unsigned long flags;
spin_lock_irqsave(&atimer->lock, flags);
atimer->irq_handling = 1;
do {
update = ct_xfitimer_reprogram(atimer, 1);
spin_unlock(&atimer->lock);
if (update)
ct_xfitimer_check_period(atimer);
spin_lock(&atimer->lock);
} while (atimer->reprogram);
atimer->irq_handling = 0;
spin_unlock_irqrestore(&atimer->lock, flags);
}
static void ct_xfitimer_prepare(struct ct_timer_instance *ti)
{
ti->frag_count = ti->substream->runtime->period_size;
ti->running = 0;
ti->need_update = 0;
}
/* start/stop the timer */
static void ct_xfitimer_update(struct ct_timer *atimer)
{
unsigned long flags;
spin_lock_irqsave(&atimer->lock, flags);
if (atimer->irq_handling) {
/* reached from IRQ handler; let it handle later */
atimer->reprogram = 1;
spin_unlock_irqrestore(&atimer->lock, flags);
return;
}
ct_xfitimer_irq_stop(atimer);
ct_xfitimer_reprogram(atimer, 0);
spin_unlock_irqrestore(&atimer->lock, flags);
}
static void ct_xfitimer_start(struct ct_timer_instance *ti)
{
struct ct_timer *atimer = ti->timer_base;
unsigned long flags;
spin_lock_irqsave(&atimer->lock, flags);
if (list_empty(&ti->running_list))
atimer->wc = ct_xfitimer_get_wc(atimer);
ti->running = 1;
ti->need_update = 0;
list_add(&ti->running_list, &atimer->running_head);
spin_unlock_irqrestore(&atimer->lock, flags);
ct_xfitimer_update(atimer);
}
static void ct_xfitimer_stop(struct ct_timer_instance *ti)
{
struct ct_timer *atimer = ti->timer_base;
unsigned long flags;
spin_lock_irqsave(&atimer->lock, flags);
list_del_init(&ti->running_list);
ti->running = 0;
spin_unlock_irqrestore(&atimer->lock, flags);
ct_xfitimer_update(atimer);
}
static void ct_xfitimer_free_global(struct ct_timer *atimer)
{
ct_xfitimer_irq_stop(atimer);
}
static const struct ct_timer_ops ct_xfitimer_ops = {
.prepare = ct_xfitimer_prepare,
.start = ct_xfitimer_start,
.stop = ct_xfitimer_stop,
.interrupt = ct_xfitimer_callback,
.free_global = ct_xfitimer_free_global,
};
/*
* timer instance
*/
struct ct_timer_instance *
ct_timer_instance_new(struct ct_timer *atimer, struct ct_atc_pcm *apcm)
{
struct ct_timer_instance *ti;
ti = kzalloc(sizeof(*ti), GFP_KERNEL);
if (!ti)
return NULL;
spin_lock_init(&ti->lock);
INIT_LIST_HEAD(&ti->instance_list);
INIT_LIST_HEAD(&ti->running_list);
ti->timer_base = atimer;
ti->apcm = apcm;
ti->substream = apcm->substream;
if (atimer->ops->init)
atimer->ops->init(ti);
spin_lock_irq(&atimer->list_lock);
list_add(&ti->instance_list, &atimer->instance_head);
spin_unlock_irq(&atimer->list_lock);
return ti;
}
void ct_timer_prepare(struct ct_timer_instance *ti)
{
if (ti->timer_base->ops->prepare)
ti->timer_base->ops->prepare(ti);
ti->position = 0;
ti->running = 0;
}
void ct_timer_start(struct ct_timer_instance *ti)
{
struct ct_timer *atimer = ti->timer_base;
atimer->ops->start(ti);
}
void ct_timer_stop(struct ct_timer_instance *ti)
{
struct ct_timer *atimer = ti->timer_base;
atimer->ops->stop(ti);
}
void ct_timer_instance_free(struct ct_timer_instance *ti)
{
struct ct_timer *atimer = ti->timer_base;
atimer->ops->stop(ti); /* to be sure */
if (atimer->ops->free_instance)
atimer->ops->free_instance(ti);
spin_lock_irq(&atimer->list_lock);
list_del(&ti->instance_list);
spin_unlock_irq(&atimer->list_lock);
kfree(ti);
}
/*
* timer manager
*/
static void ct_timer_interrupt(void *data, unsigned int status)
{
struct ct_timer *timer = data;
/* Interval timer interrupt */
if ((status & IT_INT) && timer->ops->interrupt)
timer->ops->interrupt(timer);
}
struct ct_timer *ct_timer_new(struct ct_atc *atc)
{
struct ct_timer *atimer;
struct hw *hw;
atimer = kzalloc(sizeof(*atimer), GFP_KERNEL);
if (!atimer)
return NULL;
spin_lock_init(&atimer->lock);
spin_lock_init(&atimer->list_lock);
INIT_LIST_HEAD(&atimer->instance_head);
INIT_LIST_HEAD(&atimer->running_head);
atimer->atc = atc;
hw = atc->hw;
if (!use_system_timer && hw->set_timer_irq) {
dev_info(atc->card->dev, "Use xfi-native timer\n");
atimer->ops = &ct_xfitimer_ops;
hw->irq_callback_data = atimer;
hw->irq_callback = ct_timer_interrupt;
} else {
dev_info(atc->card->dev, "Use system timer\n");
atimer->ops = &ct_systimer_ops;
}
return atimer;
}
void ct_timer_free(struct ct_timer *atimer)
{
struct hw *hw = atimer->atc->hw;
hw->irq_callback = NULL;
if (atimer->ops->free_global)
atimer->ops->free_global(atimer);
kfree(atimer);
}