incubator-nuttx/sched/irq/irq_attach.c

133 lines
4.1 KiB
C

/****************************************************************************
* sched/irq/irq_attach.c
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership. The
* ASF licenses this file to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance with the
* License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <errno.h>
#include <nuttx/irq.h>
#include "irq/irq.h"
/****************************************************************************
* 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, FAR void *arg)
{
#if NR_IRQS > 0
int ret = -EINVAL;
if ((unsigned)irq < NR_IRQS)
{
irqstate_t flags;
int ndx;
#ifdef CONFIG_ARCH_MINIMAL_VECTORTABLE
/* Is there a mapping for this IRQ number? */
ndx = g_irqmap[irq];
if ((unsigned)ndx >= CONFIG_ARCH_NUSER_INTERRUPTS)
{
/* No.. then return failure. */
return ret;
}
#else
ndx = irq;
#endif
/* 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.
*/
flags = spin_lock_irqsave(NULL);
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;
arg = NULL;
}
#ifdef CONFIG_IRQCHAIN
/* Save the new ISR and its argument in the table.
* If there is only one ISR on this irq, then .handler point to the ISR
* and .arg point to the ISR parameter; Otherwise, .handler point to
* irqchain_dispatch and .arg point to irqchain_s.
*/
if (is_irqchain(ndx, isr))
{
ret = irqchain_attach(ndx, isr, arg);
spin_unlock_irqrestore(NULL, flags);
return ret;
}
#endif
/* Save the new ISR and its argument in the table. */
g_irqvector[ndx].handler = isr;
g_irqvector[ndx].arg = arg;
#ifdef CONFIG_SCHED_IRQMONITOR
g_irqvector[ndx].start = clock_systime_ticks();
g_irqvector[ndx].time = 0;
g_irqvector[ndx].count = 0;
#endif
spin_unlock_irqrestore(NULL, flags);
ret = OK;
}
return ret;
#else
return OK;
#endif
}