/****************************************************************************
* include/nuttx/watchdog.h
*
* Copyright (C) 2012 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* 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.
*
****************************************************************************/
#ifndef __INCLUDE_NUTTX_WATCHDOG_H
#define __INCLUDE_NUTTX_WATCHDOG_H
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <nuttx/compiler.h>
#include <nuttx/irq.h>
#include <nuttx/fs/ioctl.h>
#ifdef CONFIG_WATCHDOG
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/* IOCTL Commands ***********************************************************/
/* The watchdog driver uses a standard character driver framework. However,
* since the watchdog driver is a device control interface and not a data
* transfer interface, the majority of the functionality is implemented in
* driver ioctl calls. The watchdog ioctl commands are lised below:
*
* These are detected and handled by the "upper half" watchdog timer driver.
*
* WDIOC_START - Start the watchdog timer
* Argument: Ignored
* WDIOC_STOP - Stop the watchdog timer
* Argument: Ignored
* WDIOC_GETSTATUS - Get the status of the watchdog timer.
* Argument: A writeable pointer to struct watchdog_status_s.
* WDIOC_SETTIMEOUT - Reset the watchdog timeout to this value
* Argument: A 32-bit timeout value in milliseconds.
* WDIOC_CAPTURE - Do not reset. Instead, called this handler.
* Argument: A pointer to struct watchdog_capture_s.
* WDIOC_KEEPALIVE - Reset the watchdog timer ("ping", "pet the dog");
* Argument: Ignored
*
* These may be supported by certain "lower half" drivers
*
* WDIOC_MINTIME - Set the minimum ping time. If two keepalive ioctls
* are received within this time, a reset event will
* be generated. This feature should assume to be
* disabled after WDIOC_SETTIMEOUT.
* Argument: A 32-bit time value in milliseconds.
*/
#define WDIOC_START _WDIOC(0x001)
#define WDIOC_STOP _WDIOC(0x002)
#define WDIOC_GETSTATUS _WDIOC(0x003)
#define WDIOC_SETTIMEOUT _WDIOC(0x004)
#define WDIOC_CAPTURE _WDIOC(0x005)
#define WDIOC_KEEPALIVE _WDIOC(0x006)
#define WDIOC_MINTIME _WDIOC(0x080)
/* Bit Settings *************************************************************/
/* Bit settings for the struct watchdog_status_s flags field */
#define WDFLAGS_ACTIVE (1 << 0) /* 1=The watchdog timer is running */
#define WDFLAGS_RESET (1 << 1) /* 1=Reset when the watchog timer expires */
#define WDFLAGS_CAPTURE (1 << 2) /* 1=Call the user function when the
* watchdog timer expires */
/****************************************************************************
* Public Types
****************************************************************************/
/* This is the type of the argument passed to the WDIOC_CAPTURE ioctl */
struct watchdog_capture_s
{
CODE xcpt_t newhandler; /* The new watchdog capture handler */
CODE xcpt_t oldhandler; /* The previous watchdog capture handler (if any) */
};
/* This is the type of the argument passed to the WDIOC_GETSTATUS ioctl and
* and returned by the "lower half" getstatus() method.
*/
struct watchdog_status_s
{
uint32_t flags; /* See WDFLAGS_* definitions above */
uint32_t timeout; /* The current timeout setting (in milliseconds) */
uint32_t timeleft; /* Time left until the watchdog expiration
* (in milliseconds) */
};
/* This structure provides the "lower-half" driver operations available to
* the "upper-half" driver.
*/
struct watchdog_lowerhalf_s;
struct watchdog_ops_s
{
/* Required methods ********************************************************/
/* Start the watchdog timer, resetting the time to the current timeout */
CODE int (*start)(FAR struct watchdog_lowerhalf_s *lower);
/* Stop the watchdog timer */
CODE int (*stop)(FAR struct watchdog_lowerhalf_s *lower);
/* Optional methods ********************************************************/
/* Reset the watchdog timer to the current timeout value, prevent any
* imminent watchdog timeouts. This is sometimes referred as "pinging" the
* watchdog timer or "petting the dog".
*/
CODE int (*keepalive)(FAR struct watchdog_lowerhalf_s *lower);
/* Get the current watchdog timer status */
CODE int (*getstatus)(FAR struct watchdog_lowerhalf_s *lower,
FAR struct watchdog_status_s *status);
/* Set a new timeout value (and reset the watchdog timer) */
CODE int (*settimeout)(FAR struct watchdog_lowerhalf_s *lower,
uint32_t timeout);
/* Don't reset on watchdog timer timeout; instead, call this user provider
* timeout handler. NOTE: Providing handler==NULL will restore the reset
* behavior.
*/
CODE xcpt_t (*capture)(FAR struct watchdog_lowerhalf_s *lower,
CODE xcpt_t handler);
/* Any ioctl commands that are not recognized by the "upper-half" driver
* are forwarded to the lower half driver through this method.
*/
CODE int (*ioctl)(FAR struct watchdog_lowerhalf_s *lower, int cmd,
unsigned long arg);
};
/* This structure provides the publicly visible representation of the
* "lower-half" driver state structure. "lower half" drivers will have an
* internal structure definition that will be cast-compatible with this
* structure definitions.
*/
struct watchdog_lowerhalf_s
{
/* Publicly visible portion of the "lower-half" driver state structure. */
FAR const struct watchdog_ops_s *ops; /* Lower half operations */
/* The remainder of the structure is used by the "lower-half" driver
* for whatever state storage that it may need.
*/
};
/****************************************************************************
* Public Data
****************************************************************************/
/****************************************************************************
* Public Function Prototypes
****************************************************************************/
#ifdef __cplusplus
#define EXTERN extern "C"
extern "C"
{
#else
#define EXTERN extern
#endif
/****************************************************************************
* "Upper-Half" Watchdog Driver Interfaces
****************************************************************************/
/****************************************************************************
* Name: watchdog_register
*
* Description:
* This function binds an instance of a "lower half" watchdog driver with the
* "upper half" watchdog device and registers that device so that can be used
* by application code.
*
* When this function is called, the "lower half" driver should be in the
* disabled state (as if the stop() method had already been called).
*
* NOTE: Normally, this function would not be called by application code.
* Rather it is called indirectly through the architecture-specific
* interface up_wdginitialize() described below.
*
* Input parameters:
* dev path - The full path to the driver to be registers in the NuttX
* pseudo-filesystem. The recommended convention is to name all watchdog
* drivers as "/dev/watchdog0", "/dev/watchdog1", etc. where the driver
* path differs only in the "minor" number at the end of the device name.
* lower - A pointer to an instance of lower half watchdog driver. This
* instance is bound to the watchdog driver and must persists as long as
* the driver persists.
*
* Returned Value:
* On success, a non-NULL handle is returned to the caller. In the event
* of any failure, a NULL value is returned.
*
****************************************************************************/
FAR void *watchdog_register(FAR const char *path,
FAR struct watchdog_lowerhalf_s *lower);
/****************************************************************************
* Name: watchdog_unregister
*
* Description:
* This function can be called to disable and unregister the watchdog
* device driver.
*
* Input parameters:
* handle - This is the handle that was returned by watchdog_register()
*
* Returned Value:
* None
*
****************************************************************************/
void watchdog_unregister(FAR void *handle);
/****************************************************************************
* Platform-Independent "Lower-Half" Watchdog Driver Interfaces
****************************************************************************/
/****************************************************************************
* Architecture-specific Application Interfaces
****************************************************************************/
/****************************************************************************
* Name: up_wdginitialize()
*
* Description:
* Perform architecture-specific initialization of the Watchdog hardware.
* This interface should be provided by all configurations using
* to avoid exposed platform-dependent logic.
*
* At a minimum, this function should call watchdog_register() which is
* described above.
*
* Input parameters:
* None
*
* Returned Value:
* Zero on success; a negated errno value on failure.
*
****************************************************************************/
int up_wdginitialize(void);
#undef EXTERN
#ifdef __cplusplus
}
#endif
#endif /* CONFIG_WATCHDOG */
#endif /* __INCLUDE_NUTTX_WATCHDOG_H */
