incubator-nuttx/sched/irq_attach.c

128 lines
4.8 KiB
C

/****************************************************************************
* sched/irq_attach.c
*
* Copyright (C) 2007-2008, 2010, 2012 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. 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.
* 3. Neither the name NuttX 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.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <nuttx/irq.h>
#include "irq_internal.h"
/****************************************************************************
* Definitions
****************************************************************************/
/****************************************************************************
* Private Type Declarations
****************************************************************************/
/****************************************************************************
* Global Variables
****************************************************************************/
/****************************************************************************
* Private Variables
****************************************************************************/
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: irq_attach
*
* Description:
* Configure the IRQ subsystem so that IRQ number 'irq' is dispatched to
* 'isr'
*
****************************************************************************/
int irq_attach(int irq, xcpt_t isr)
{
#if NR_IRQS > 0
int ret = ERROR;
if ((unsigned)irq < NR_IRQS)
{
irqstate_t state;
/* If the new ISR is NULL, then the ISR is being detached.
* In this case, disable the ISR and direct any interrupts
* to the unexpected interrupt handler.
*/
state = irqsave();
if (isr == NULL)
{
/* Disable the interrupt if we can before detaching it. We might
* not be able to do this if: (1) the device does not have a
* centralized interrupt controller (so up_disable_irq() is not
* supported). Or (2) if the device has different number for vector
* numbers and IRQ numbers (in that case, we don't know the correct
* IRQ number to use to disable the interrupt). In those cases, the
* code will just need to be careful that it disables all interrupt
* sources before detaching from the interrupt vector.
*/
#if !defined(CONFIG_ARCH_NOINTC) && !defined(CONFIG_ARCH_VECNOTIRQ)
up_disable_irq(irq);
#endif
/* Detaching the ISR really means re-attaching it to the
* unexpected exception handler.
*/
isr = irq_unexpected_isr;
}
/* Save the new ISR in the table. */
g_irqvector[irq] = isr;
irqrestore(state);
ret = OK;
}
return ret;
#else
return OK;
#endif
}