incubator-nuttx/include/nuttx/wdog.h

170 lines
5.6 KiB
C

/****************************************************************************
* include/nuttx/wdog.h
*
* 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.
*
****************************************************************************/
#ifndef __INCLUDE_NUTTX_WDOG_H
#define __INCLUDE_NUTTX_WDOG_H
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <stdint.h>
#include <queue.h>
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
#define WDOG_ISACTIVE(w) ((w)->func != NULL)
/****************************************************************************
* Public Type Declarations
****************************************************************************/
/* The arguments are passed as scalar wdparm_t values. For systems where
* the sizeof(pointer) < sizeof(uint32_t), the following union defines the
* alignment of the pointer within the uint32_t. For example, the SDCC
* MCS51 general pointer is 24-bits, but uint32_t is 32-bits (of course).
*
* We always have sizeof(pointer) <= sizeof(uintptr_t) by definition.
*/
#if UINTPTR_MAX >= UINT32_MAX
typedef uintptr_t wdparm_t;
#else
typedef uint32_t wdparm_t;
#endif
/* This is the form of the function that is called when the
* watchdog function expires.
*/
typedef CODE void (*wdentry_t)(wdparm_t arg);
/* This is the internal representation of the watchdog timer structure. */
struct wdog_s
{
FAR struct wdog_s *next; /* Support for singly linked lists. */
wdentry_t func; /* Function to execute when delay expires */
#ifdef CONFIG_PIC
FAR void *picbase; /* PIC base address */
#endif
int lag; /* Timer associated with the delay */
wdparm_t arg; /* Callback argument */
};
/****************************************************************************
* Pubic Function Prototypes
****************************************************************************/
#ifdef __cplusplus
#define EXTERN extern "C"
extern "C"
{
#else
#define EXTERN extern
#endif
/****************************************************************************
* Name: wd_start
*
* Description:
* This function adds a watchdog timer to the actuve timer queue. The
* specified watchdog function at 'wdentry' will be called from the
* interrupt level after the specified number of ticks has elapsed.
* Watchdog timers may be started from the interrupt level.
*
* Watchdog timers execute in the address environment that was in effect
* when wd_start() is called.
*
* Watchdog timers execute only once.
*
* To replace either the timeout delay or the function to be executed,
* call wd_start again with the same wdog; only the most recent wdStart()
* on a given watchdog ID has any effect.
*
* Input Parameters:
* wdog - Watchdog ID
* delay - Delay count in clock ticks
* wdentry - Function to call on timeout
* arg - Parameter to pass to wdentry.
*
* NOTE: The parameter must be of type wdparm_t.
*
* Returned Value:
* Zero (OK) is returned on success; a negated errno value is return to
* indicate the nature of any failure.
*
* Assumptions:
* The watchdog routine runs in the context of the timer interrupt handler
* and is subject to all ISR restrictions.
*
****************************************************************************/
int wd_start(FAR struct wdog_s *wdog, int32_t delay,
wdentry_t wdentry, wdparm_t arg);
/****************************************************************************
* Name: wd_cancel
*
* Description:
* This function cancels a currently running watchdog timer. Watchdog
* timers may be cancelled from the interrupt level.
*
* Input Parameters:
* wdog - ID of the watchdog to cancel.
*
* Returned Value:
* Zero (OK) is returned on success; A negated errno value is returned to
* indicate the nature of any failure.
*
****************************************************************************/
int wd_cancel(FAR struct wdog_s *wdog);
/****************************************************************************
* Name: wd_gettime
*
* Description:
* This function returns the time remaining before the specified watchdog
* timer expires.
*
* Input Parameters:
* wdog - watchdog ID
*
* Returned Value:
* The time in system ticks remaining until the watchdog time expires.
* Zero means either that wdog is not valid or that the wdog has already
* expired.
*
****************************************************************************/
int wd_gettime(FAR struct wdog_s *wdog);
#undef EXTERN
#ifdef __cplusplus
}
#endif
#endif /* __INCLUDE_NUTTX_WDOG_H */