diff options
Diffstat (limited to 'nuttx/include')
| -rw-r--r-- | nuttx/include/nuttx/clock.h | 42 |
1 files changed, 37 insertions, 5 deletions
diff --git a/nuttx/include/nuttx/clock.h b/nuttx/include/nuttx/clock.h index 472ff3bfc..952e0e5ef 100644 --- a/nuttx/include/nuttx/clock.h +++ b/nuttx/include/nuttx/clock.h @@ -1,8 +1,8 @@ /**************************************************************************** * include/nuttx/clock.h * - * Copyright (C) 2007-2009, 2011 Gregory Nutt. All rights reserved. - * Author: Gregory Nutt <spudmonkey@racsa.co.cr> + * Copyright (C) 2007-2009, 2011-2012 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 @@ -33,8 +33,8 @@ * ****************************************************************************/ -#ifndef __NUTTX_CLOCK_H -#define __NUTTX_CLOCK_H +#ifndef _INCLUDE_NUTTX_CLOCK_H +#define _INCLUDE_NUTTX_CLOCK_H /**************************************************************************** * Included Files @@ -161,6 +161,38 @@ extern "C" { #endif /**************************************************************************** + * Function: clock_synchronize + * + * Description: + * Synchronize the system timer to a hardware RTC. This operation is + * normally performed automatically by the system during clock + * initialization. However, the user may also need to explicitly re- + * synchronize the system timer to the RTC under certain conditions where + * the system timer is known to be in error. For example, in certain low- + * power states, the system timer may be stopped but the RTC will continue + * keep correct time. After recovering from such low-power state, this + * function should be called to restore the correct system time. + * + * Calling this function could result in system time going "backward" in + * time, especially with certain lower resolution RTC implementations. + * Time going backward could have bad consequences if there are ongoing + * timers and delays. So use this interface with care. + * + * Parameters: + * None + * + * Return Value: + * None + * + * Assumptions: + * + ****************************************************************************/ + +#ifdef CONFIG_RTC +EXTERN void clock_synchronize(void); +#endif + +/**************************************************************************** * Function: clock_systimer * * Description: @@ -216,4 +248,4 @@ EXTERN uint64_t clock_systimer64(void); #endif #endif /* !CONFIG_DISABLE_CLOCK */ -#endif /* __NUTTX_CLOCK_H */ +#endif /* _INCLUDE_NUTTX_CLOCK_H */ |