unplugged-kernel/drivers/misc/mediatek/ccci_util/ccci_util_lib_time.c

67 lines
1.5 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2015 MediaTek Inc.
*/
#include <linux/module.h>
#include <linux/device.h>
#include <linux/spinlock.h>
#include "mt-plat/mtk_ccci_common.h"
#include <linux/wait.h>
static wait_queue_head_t time_update_notify_queue_head;
static spinlock_t wait_count_lock;
static unsigned int wait_count;
static unsigned int get_update;
static unsigned int api_ready;
void ccci_timer_for_md_init(void)
{
init_waitqueue_head(&time_update_notify_queue_head);
spin_lock_init(&wait_count_lock);
wait_count = 0;
get_update = 0;
/* update in order */
mb();
api_ready = 1;
}
int wait_time_update_notify(void)
{ /* Only support one wait currently */
int ret = -1;
unsigned long flags;
if (api_ready) {
/* Update wait count ++ */
spin_lock_irqsave(&wait_count_lock, flags);
wait_count++;
spin_unlock_irqrestore(&wait_count_lock, flags);
ret = wait_event_interruptible(
time_update_notify_queue_head,
get_update);
if (ret != -ERESTARTSYS)
get_update = 0;
/* Update wait count -- */
spin_lock_irqsave(&wait_count_lock, flags);
wait_count--;
spin_unlock_irqrestore(&wait_count_lock, flags);
}
return ret;
}
EXPORT_SYMBOL(wait_time_update_notify);
void notify_time_update(void)
{
unsigned long flags;
if (!api_ready)
return; /* API not ready */
get_update = 1;
spin_lock_irqsave(&wait_count_lock, flags);
if (wait_count)
wake_up_all(&time_update_notify_queue_head);
spin_unlock_irqrestore(&wait_count_lock, flags);
}