px4-firmware/nuttx/sched/wd_initialize.c

139 lines
4.7 KiB
C

/************************************************************************
* sched/wd_initialize.c
*
* Copyright (C) 2007, 2009 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <spudmonkey@racsa.co.cr>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* 3. Neither the name NuttX nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
************************************************************************/
/************************************************************************
* Included Files
************************************************************************/
#include <nuttx/config.h>
#include <queue.h>
#include <nuttx/kmalloc.h>
#include "os_internal.h"
#include "wd_internal.h"
/************************************************************************
* Definitions
************************************************************************/
/************************************************************************
* Private Type Declarations
************************************************************************/
/************************************************************************
* Global Variables
************************************************************************/
/* 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;
/* g_wdpool is a pointer to a list of pre-allocated watchdogs.
* The number of watchdogs in the pool is a configuration
* item.
*/
FAR wdog_t *g_wdpool;
/* 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;
/************************************************************************
* Private Variables
************************************************************************/
/************************************************************************
* Private Functions
************************************************************************/
/************************************************************************
* Public Functions
************************************************************************/
/************************************************************************
* Function: wd_initialize
*
* Description:
* This function initalized the watchdog data structures
*
* Parameters:
* None
*
* Return 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)
{
/* Initialize the free watchdog list */
sq_init(&g_wdfreelist);
/* The g_wdfreelist must be loaded at initialization time to hold the
* configured number of watchdogs.
*/
g_wdpool = (FAR wdog_t*)kmalloc(sizeof(wdog_t) * CONFIG_PREALLOC_WDOGS);
if (g_wdpool)
{
FAR wdog_t *wdog = g_wdpool;
int i;
for (i = 0; i < CONFIG_PREALLOC_WDOGS; i++)
{
sq_addlast((FAR sq_entry_t*)wdog++, &g_wdfreelist);
}
}
/* The g_wdactivelist queue must be reset at initialization time. */
sq_init(&g_wdactivelist);
}