Real Time Clock

[Thomas Doerfler]

Hi,

I think it makes sense to convert the rtc access functions to
standardized "*_read" and "*_write" functions in the classic API driver
IF (instead of dedicated functions).

It may surely make sense to map the POSIX timer functions to that device.

Any further comments?

wkr,
Thomas.

Sebastian Huber wrote:
> Hi,
> 
> in order to support the POSIX clock_gettime(), clock_settime() and
> clock_getres() functions we need a RTC driver interface which can at least read
>  and set the RTC.  An interface proposal follows:
> 
> /**
>  * @file
>  *
>  * Real-time clock driver interface.
>  */
> 
> /*
>  *  COPYRIGHT (c) 1989-2001.
>  *  On-Line Applications Research Corporation (OAR).
>  *
>  *  The license and distribution terms for this file may be
>  *  found in the file LICENSE in this distribution or at
>  *  http://www.rtems.com/license/LICENSE.
>  *
>  *  $Id: rtc.h,v 1.4 2005/01/28 08:04:27 ralf Exp $
>  */
> 
> #ifndef _RTEMS_RTC_H
> #define _RTEMS_RTC_H
> 
> #include <rtems.h>
> 
> #ifdef __cplusplus
> extern "C" {
> #endif
> 
> /**
>  * @defgroup rtems_rtc Real-Time Clock Driver Interface
>  *
>  * This driver interface provides support to read and set the real-time clock
>  * and to initialize the time of day for the system.
>  *
>  * @{
>  */
> 
> /**
>  * Device file name path.
>  */
> #define RTC_DEVICE_NAME "/dev/rtc"
> 
> /**
>  * Device driver table entry.
>  */
> #define RTC_DRIVER_TABLE_ENTRY \
>   { rtc_initialize, rtc_open, rtc_close, \
>     rtc_read, rtc_write, rtc_control }
> 
> /**
>  * Initializes the real-time clock device and sets the time of day for the
>  * system.
>  *
>  * If the real-time clock provides an invalid time of day value the system time
>  * of day must remain untouched.
>  */
> rtems_device_driver rtc_initialize(
>   rtems_device_major_number,
>   rtems_device_minor_number,
>   void *
> );
> 
> /**
>  * Opens the real-time clock device.
>  */
> rtems_device_driver rtc_open(
>   rtems_device_major_number,
>   rtems_device_minor_number,
>   void *
> );
> 
> /**
>  * Closes the real-time clock device.
>  */
> rtems_device_driver rtc_close(
>   rtems_device_major_number,
>   rtems_device_minor_number,
>   void *
> );
> 
> /**
>  * Reads the real-time clock value.
>  *
>  * The value will be returned in a @ref rtems_time_of_day structure.
>  */
> rtems_device_driver rtc_read(
>   rtems_device_major_number,
>   rtems_device_minor_number,
>   void *
> );
> 
> /**
>  * Sets the real-time clock value.
>  *
>  * The value will be set from a @ref rtems_time_of_day structure.
>  */
> rtems_device_driver rtc_write(
>   rtems_device_major_number,
>   rtems_device_minor_number,
>   void *
> );
> 
> /**
>  * Controls the real-time clock.
>  */
> rtems_device_driver rtc_control(
>   rtems_device_major_number,
>   rtems_device_minor_number,
>   void *
> );
> 
> /** @} */
> 
> #ifdef __cplusplus
> }
> #endif
> 
> #endif
> 


-- 

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Thomas Doerfler        Obere Lagerstrasse 30
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