Subversion Repositories openrisc

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

//

//      synth_watchdog.cxx

//

//      Watchdog driver for the synthetic target

//

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

//####ECOSGPLCOPYRIGHTBEGIN####

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

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

// Copyright (C) 2002 Bart Veer

//

// 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.,

// 59 Temple Place, Suite 330, Boston, MA 02111-1307 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.

//

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

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

//

// Alternative licenses for eCos may be arranged by contacting the

// copyright holder(s).

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

//####ECOSGPLCOPYRIGHTEND####

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

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

//

// Author(s):    bartv

// Contributors: bartv

// Date:         2002-09-04

//

//####DESCRIPTIONEND####

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

#include <pkgconf/system.h>

#include <pkgconf/devs_watchdog_synth.h>

#ifdef CYGIMP_WATCHDOG_HARDWARE

#include <cyg/hal/hal_arch.h>

#include <cyg/infra/cyg_type.h>

#include <cyg/infra/cyg_ass.h>

#include <cyg/infra/diag.h>

#include <cyg/hal/hal_io.h>

// FIXME: right now the generic watchdog header depends on the

// kernel. That should be fixed in the watchdog code, but will

// affect some device drivers as well

#include <pkgconf/kernel.h>

#include <cyg/io/watchdog.hxx>

// Protocol between host and target

#define SYNTH_WATCHDOG_START    0x01

#define SYNTH_WATCHDOG_RESET    0x02

// The synthetic target's watchdog implementation involves interaction

// with a watchdog.tcl script running in the I/O auxiliary. The device

// must be instantiated during system initialization, preferably via

// a prioritized C++ static constructor. The generic watchdog package

// does have a static object, but it is not prioritized. If

// CYGSEM_HAL_STOP_CONSTRUCTORS_ON_FLAG is enabled then that object's

// constructor would get called too late.

//

// Instead a private class is defined here, and once instance is created.

// That instance gets referenced by the Cyg_Watchdog members, so

// selective linking does not get in the way. Instantiation happens inside

// the constructor, and the main Cyg_Watchdog::start() and reset() functions

// involve passing a message to the host-side.

//

// There is an open issue re. resolution. Usually the hardware imposes

// limits on what resolutions are valid, in fact there may be only one.

// With the synthetic target it would be possible to configure the

// desired resolution either on the target-side using a CDL option, or

// on the host-side using the target definition file. The resolution

// would have to be fairly coarse, probably at least 0.1 seconds,

// to allow for communication overheads. It is not clear whether

// target-side or host-side configuration is more appropriate, so for

// now a fixed resolution of one second is used.

class _Synth_Watchdog {

  public:

    _Synth_Watchdog();

    ~_Synth_Watchdog() { }

    cyg_uint64  resolution;

};

// A static instance of the _Synth_Watchdog class, whose constructor will

// be called at the right time to instantiate host-side support.

static _Synth_Watchdog _synth_watchdog_object CYGBLD_ATTRIB_INIT_PRI(CYG_INIT_DRIVERS);

// Id for communicating with the watchdog instance in the auxiliary

static int aux_id   = -1;

_Synth_Watchdog::_Synth_Watchdog()

{

    // SIGPWR is disabled by default. It has to be reenabled.

    struct cyg_hal_sys_sigset_t blocked;

    CYG_HAL_SYS_SIGEMPTYSET(&blocked);

    CYG_HAL_SYS_SIGADDSET(&blocked, CYG_HAL_SYS_SIGPWR);

    cyg_hal_sys_sigprocmask(CYG_HAL_SYS_SIG_UNBLOCK, &blocked, (cyg_hal_sys_sigset_t*) 0);

    resolution = 1000000000LL;

    if (synth_auxiliary_running) {

        aux_id  = synth_auxiliary_instantiate("devs/watchdog/synth",

                                              SYNTH_MAKESTRING(CYGPKG_DEVS_WATCHDOG_SYNTH),

                                              "watchdog",

                                              (const char*) 0,

                                              (const char*) 0);

    }

}

// Hardware initialization. This has already happened in the

// _Synth_Watchdog constructor, all that is needed here is to

// propagate the resolution.

void

Cyg_Watchdog::init_hw(void)

{

    resolution  = _synth_watchdog_object.resolution;

}

void

Cyg_Watchdog::start(void)

{

    if (synth_auxiliary_running && (-1 != aux_id)) {

        synth_auxiliary_xchgmsg(aux_id, SYNTH_WATCHDOG_START, 0, 0,

                               (const unsigned char*)0, 0,

                               (int *) 0,

                               (unsigned char*) 0, (int*) 0, 0);

    }

}

void

Cyg_Watchdog::reset()

{

    if (synth_auxiliary_running && (-1 != aux_id)) {

        synth_auxiliary_xchgmsg(aux_id, SYNTH_WATCHDOG_RESET, 0, 0,

                               (const unsigned char*)0, 0,

                               (int *) 0,

                               (unsigned char*) 0, (int*) 0, 0);

    }

}

#endif // CYGIMP_WATCHDOG_HARDWARE