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/******************************************************************************

*                                                                             *

* License Agreement                                                           *

*                                                                             *

* Copyright (c) 2009      Altera Corporation, San Jose, California, USA.      *

* All rights reserved.                                                        *

*                                                                             *

* Permission is hereby granted, free of charge, to any person obtaining a     *

* copy of this software and associated documentation files (the "Software"),  *

* to deal in the Software without restriction, including without limitation   *

* the rights to use, copy, modify, merge, publish, distribute, sublicense,    *

* and/or sell copies of the Software, and to permit persons to whom the       *

* Software is furnished to do so, subject to the following conditions:        *

*                                                                             *

* The above copyright notice and this permission notice shall be included in  *

* all copies or substantial portions of the Software.                         *

*                                                                             *

* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR  *

* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,    *

* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE *

* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER      *

* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING     *

* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER         *

* DEALINGS IN THE SOFTWARE.                                                   *

*                                                                             *

* This agreement shall be governed in all respects by the laws of the State   *

* of California and by the laws of the United States of America.              *

*                                                                             *

* Altera does not recommend, suggest or require that this reference design    *

* file be used in conjunction or combination with any other product.          *

******************************************************************************/

#include <errno.h>

#include "system.h"

/*

 * This interrupt registry mechanism works with the Nios II internal interrupt

 * controller (IIC) only. Systems with an external interrupt controller (EIC),

 * or those with the IIC who are using the enhanced interrupt API will

 * utilize the alt_ic_isr_register() routine to register an interrupt.

 */

#ifndef NIOS2_EIC_PRESENT

#include "sys/alt_irq.h"

#include "priv/alt_legacy_irq.h"

#include "os/alt_hooks.h"

#include "alt_types.h"

/*

 * The header, alt_irq_entry.h, contains the exception entry point, and is

 * provided by the processor component. It is included here, so that the code

 * will be added to the executable only if alt_irq_register() is present, i.e.

 * if no interrupts are registered - there's no need to provide any

 * interrupt handling.

 */

#include "sys/alt_irq_entry.h"

/*

 * The header, alt_irq_table.h contains a table describing which function

 * handles each interrupt.

 */

#include "priv/alt_irq_table.h"

/*

 * alt_irq_handler() is called to register an interrupt handler. If the

 * function is succesful, then the requested interrupt will be enabled upon

 * return. Registering a NULL handler will disable the interrupt.

 *

 * The return value is 0 if the interrupt handler was registered and the

 * interrupt was enabled, otherwise it is negative.

 */

int alt_irq_register (alt_u32 id,

                      void* context,

                      alt_isr_func handler)

{

  int rc = -EINVAL;

  alt_irq_context status;

  if (id < ALT_NIRQ)

  {

    /*

     * interrupts are disabled while the handler tables are updated to ensure

     * that an interrupt doesn't occur while the tables are in an inconsistant

     * state.

     */

    status = alt_irq_disable_all ();

    alt_irq[id].handler = handler;

    alt_irq[id].context = context;

    rc = (handler) ? alt_irq_enable (id): alt_irq_disable (id);

    alt_irq_enable_all(status);

  }

  return rc;

}

#endif /* NIOS2_EIC_PRESENT */