Subversion Repositories openrisc

//==========================================================================

//

//      devs/wallclock/wallclock.cxx

//

//      Wallclock base

//

//==========================================================================

// ####ECOSGPLCOPYRIGHTBEGIN####                                            

// -------------------------------------------                              

// This file is part of eCos, the Embedded Configurable Operating System.   

// Copyright (C) 1998, 1999, 2000, 2001, 2002, 2009 Free Software Foundation, Inc.

//

// eCos is free software; you can redistribute it and/or modify it under    

// the terms of the GNU General Public License as published by the Free     

// Software Foundation; either version 2 or (at your option) any later      

// version.                                                                 

//

// eCos is distributed in the hope that it will be useful, but WITHOUT      

// ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or    

// FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License    

// for more details.                                                        

//

// You should have received a copy of the GNU General Public License        

// along with eCos; if not, write to the Free Software Foundation, Inc.,    

// 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.            

//

// As a special exception, if other files instantiate templates or use      

// macros or inline functions from this file, or you compile this file      

// and link it with other works to produce a work based on this file,       

// this file does not by itself cause the resulting work to be covered by   

// the GNU General Public License. However the source code for this file    

// must still be made available in accordance with section (3) of the GNU   

// General Public License v2.                                               

//

// This exception does not invalidate any other reasons why a work based    

// on this file might be covered by the GNU General Public License.         

// -------------------------------------------                              

// ####ECOSGPLCOPYRIGHTEND####                                              

//==========================================================================

//#####DESCRIPTIONBEGIN####

//

// Author(s):     jskov

// Contributors:  jskov

// Date:          2000-03-28

// Purpose:       Wallclock base driver

// Description:   This provides a generic wallclock base driver which

//                relies on sub-drivers to provide the interface functions

//                to the hardware device (see wallclock.hxx for details).

//

//                The driver can be configured to run in one of two modes:

//                  init-get mode:

//                    In this mode, the hardware driver only needs to

//                    implement a function to read the hardware clock

//                    and a (possibly empty) init function which makes

//                    sure the hardware clock is properly initialized.

//                    While the driver in this mode has a smaller memory

//                    foot-print, it does not support battery-backed up

//                    clocks.

//

//                  set-get mode:

//                    Requires both set and get functions for the hardware

//                    device. While bigger, it allows support of 

//                    battery-backed up clocks.

//

//

//####DESCRIPTIONEND####

//

//==========================================================================

#include <pkgconf/wallclock.h>          // Wallclock device config

#include <cyg/infra/cyg_type.h>         // Common type definitions and support

#include <cyg/hal/drv_api.h>            // Driver API

#include <cyg/io/wallclock.hxx>         // The WallClock API

//-----------------------------------------------------------------------------

// Local static variables

static Cyg_WallClock wallclock_instance CYGBLD_ATTRIB_INIT_PRI( CYG_INIT_DEV_WALLCLOCK );

#ifndef CYGSEM_WALLCLOCK_SET_GET_MODE

static cyg_uint32 epoch_ticks;

static cyg_uint32 epoch_time_stamp;

#endif

static cyg_drv_mutex_t wallclock_lock;

Cyg_WallClock *Cyg_WallClock::wallclock;

//-----------------------------------------------------------------------------

// Constructor

Cyg_WallClock::Cyg_WallClock()

{

    // install instance pointer

    wallclock = &wallclock_instance;

    // Initialize lock used for mutually exclusive access to hardware

    cyg_drv_mutex_init(&wallclock_lock);

    // Always allow low-level driver to initialize clock, even though it

    // may not be necessary for set-get mode.

    init_hw_seconds();

}

//-----------------------------------------------------------------------------

// Returns the number of seconds elapsed since 1970-01-01 00:00:00.

// This may involve reading the hardware, so it may take anything up to

// a second to complete.

cyg_uint32 Cyg_WallClock::get_current_time()

{

    cyg_uint32 res;

    while (!cyg_drv_mutex_lock(&wallclock_lock));

#ifdef CYGSEM_WALLCLOCK_SET_GET_MODE

    res = get_hw_seconds();

#else

    res = epoch_time_stamp + get_hw_seconds() - epoch_ticks;

#endif

    cyg_drv_mutex_unlock(&wallclock_lock);

    return res;

}

//-----------------------------------------------------------------------------

// Sets the clock. Argument is seconds elapsed since 1970-01-01 00:00:00.

// This may involve reading or writing to the hardware, so it may take

// anything up to a second to complete.

void Cyg_WallClock::set_current_time( cyg_uint32 time_stamp )

{

    while (!cyg_drv_mutex_lock(&wallclock_lock));

#ifdef CYGSEM_WALLCLOCK_SET_GET_MODE

    set_hw_seconds(time_stamp);

#else

    epoch_time_stamp    = time_stamp;

    epoch_ticks         = get_hw_seconds();

#endif

    cyg_drv_mutex_unlock(&wallclock_lock);

}

//-----------------------------------------------------------------------------

// End of devs/wallclock/wallclock.cxx