/**************************************************************************** * include/nuttx/watchdog.h * * Copyright (C) 2012 Gregory Nutt. All rights reserved. * Author: Gregory Nutt * * 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 #include #include #include #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 */