Subversion Repositories openrisc_me

/*

(C) Copyright IBM Corp. 2008

All rights reserved.

Redistribution and use in source and binary forms, with or without

modification, are permitted provided that the following conditions are met:

* Redistributions of source code must retain the above copyright notice,

this list of conditions and the following disclaimer.

* 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.

* Neither the name of IBM 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.

*/

/* SPU clock stop library service.  */

#include <spu_timer.h>

#include "spu_timer_internal.h"

/* Stops the SPU clock:

    * decrements clock start count

    * when count is zero, disables the decrementer event and stops the

      decrementer

   Returns 0 on success and  <0 on failure:

    * SPU_CLOCK_ERR_NOT_RUNNING - clock was already off

    * SPU_CLOCK_ERR_TIMERS_ACTIVE - active timers exist

    * SPU_CLOCK_ERR_STILL_RUNNING - start count was decremented but clock was

      not stopped  */

int

spu_clock_stop (void)

{

  if (__spu_clock_startcnt == 0)

    return SPU_CLOCK_ERR_NOT_RUNNING;

  if (__spu_clock_startcnt == 1 && (__spu_timers_active || __spu_timers_handled))

    return SPU_CLOCK_ERR_TIMERS_ACTIVE;

  /* Don't stop clock if the clock is still in use.  */

  if (--__spu_clock_startcnt != 0)

    return SPU_CLOCK_ERR_STILL_RUNNING;

  /* Clock stopped, stop decrementer.  */

  __disable_spu_decr ();

  /* Clock is enabled on clock start - restore to original state (saved at start).  */

  if (__likely (!__spu_clock_state_was_enabled))

    {

      spu_idisable ();

    }

  return 0;

}