incubator-nuttx/sched/wdog/wd_initialize.c

119 lines
3.6 KiB
C

/****************************************************************************
* sched/wdog/wd_initialize.c
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership. The
* ASF licenses this file to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance with the
* License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <queue.h>
#include "wdog/wdog.h"
/****************************************************************************
* Public Data
****************************************************************************/
/* The g_wdfreelist data structure is a singly linked list of watchdogs
* available to the system for delayed function use.
*/
sq_queue_t g_wdfreelist;
/* The g_wdactivelist data structure is a singly linked list ordered by
* watchdog expiration time. When watchdog timers expire,the functions on
* this linked list are removed and the function is called.
*/
sq_queue_t g_wdactivelist;
/* This is the number of free, pre-allocated watchdog structures in the
* g_wdfreelist. This value is used to enforce a reserve for interrupt
* handlers.
*/
uint16_t g_wdnfree;
/* This is wdog tickbase, for wd_gettime() may called many times
* between 2 times of wd_timer(), we use it to update wd_gettime().
*/
#ifdef CONFIG_SCHED_TICKLESS
clock_t g_wdtickbase;
#endif
/****************************************************************************
* Private Data
****************************************************************************/
/* g_wdpool is a list of pre-allocated watchdogs. The number of watchdogs
* in the pool is a configuration item.
*/
static struct wdog_s g_wdpool[CONFIG_PREALLOC_WDOGS];
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: wd_initialize
*
* Description:
* This function initializes the watchdog data structures
*
* Input Parameters:
* None
*
* Returned Value:
* None
*
* Assumptions:
* This function must be called early in the initialization sequence
* before the timer interrupt is attached and before any watchdog
* services are used.
*
****************************************************************************/
void wd_initialize(void)
{
FAR struct wdog_s *wdog = g_wdpool;
int i;
/* Initialize watchdog lists */
sq_init(&g_wdfreelist);
sq_init(&g_wdactivelist);
/* The g_wdfreelist must be loaded at initialization time to hold the
* configured number of watchdogs.
*/
for (i = 0; i < CONFIG_PREALLOC_WDOGS; i++)
{
sq_addlast((FAR sq_entry_t *)wdog++, &g_wdfreelist);
}
/* All watchdogs are free */
g_wdnfree = CONFIG_PREALLOC_WDOGS;
}