| /* |
| * Copyright (c) 2013-2014 Wind River Systems, Inc. |
| * |
| * Licensed 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. |
| */ |
| |
| /** |
| * @file |
| * @brief ARM CORTEX-M3 interrupt management |
| * |
| * |
| * Interrupt management: enabling/disabling and dynamic ISR |
| * connecting/replacing. SW_ISR_TABLE_DYNAMIC has to be enabled for |
| * connecting ISRs at runtime. |
| */ |
| |
| #include <nanokernel.h> |
| #include <arch/cpu.h> |
| #include <misc/__assert.h> |
| #include <toolchain.h> |
| #include <sections.h> |
| #include <sw_isr_table.h> |
| |
| extern void __reserved(void); |
| |
| |
| /** |
| * |
| * @brief Enable an interrupt line |
| * |
| * Clear possible pending interrupts on the line, and enable the interrupt |
| * line. After this call, the CPU will receive interrupts for the specified |
| * <irq>. |
| * |
| * @return N/A |
| */ |
| void irq_enable(unsigned int irq) |
| { |
| /* before enabling interrupts, ensure that interrupt is cleared */ |
| _NvicIrqUnpend(irq); |
| _NvicIrqEnable(irq); |
| } |
| |
| /** |
| * |
| * @brief Disable an interrupt line |
| * |
| * Disable an interrupt line. After this call, the CPU will stop receiving |
| * interrupts for the specified <irq>. |
| * |
| * @return N/A |
| */ |
| void irq_disable(unsigned int irq) |
| { |
| _NvicIrqDisable(irq); |
| } |
| |
| /** |
| * @internal |
| * |
| * @brief Set an interrupt's priority |
| * |
| * Valid values are from 1 to 255. Interrupts of priority 1 are not masked when |
| * interrupts are locked system-wide, so care must be taken when using them. ISR |
| * installed with priority 1 interrupts cannot make kernel calls. |
| * |
| * Priority 0 is reserved for kernel usage and cannot be used. |
| * |
| * The priority is verified if ASSERT_ON is enabled. |
| * |
| * @return N/A |
| */ |
| void _irq_priority_set(unsigned int irq, |
| unsigned int prio) |
| { |
| __ASSERT(prio > 0 && prio < 256, "invalid priority!"); |
| _NvicIrqPrioSet(irq, _EXC_PRIO(prio)); |
| } |
| |
| /** |
| * |
| * @brief Spurious interrupt handler |
| * |
| * Installed in all dynamic interrupt slots at boot time. Throws an error if |
| * called. |
| * |
| * See __reserved(). |
| * |
| * @return N/A |
| */ |
| void _irq_spurious(void *unused) |
| { |
| ARG_UNUSED(unused); |
| __reserved(); |
| } |
| |
| #if CONFIG_SW_ISR_TABLE_DYNAMIC |
| /** |
| * @internal |
| * |
| * @brief Replace an interrupt handler by another |
| * |
| * An interrupt's ISR can be replaced at runtime. |
| * |
| * @return N/A |
| */ |
| void _irq_handler_set(unsigned int irq, |
| void (*new)(void *arg), |
| void *arg) |
| { |
| int key = irq_lock(); |
| |
| _sw_isr_table[irq].isr = new; |
| _sw_isr_table[irq].arg = arg; |
| |
| irq_unlock(key); |
| } |
| |
| /** |
| * |
| * @brief Connect an ISR to an interrupt line |
| * |
| * <isr> is connected to interrupt line <irq> (exception #<irq>+16). No prior |
| * ISR can have been connected on <irq> interrupt line since the system booted. |
| * |
| * This routine will hang if another ISR was connected for interrupt line <irq> |
| * and ASSERT_ON is enabled; if ASSERT_ON is disabled, it will fail silently. |
| * |
| * @return the interrupt line number |
| */ |
| int irq_connect_dynamic(unsigned int irq, |
| unsigned int prio, |
| void (*isr)(void *arg), |
| void *arg, |
| uint32_t flags) |
| { |
| ARG_UNUSED(flags); |
| _irq_handler_set(irq, isr, arg); |
| _irq_priority_set(irq, prio); |
| return irq; |
| } |
| |
| /** |
| * |
| * @internal |
| * |
| * @brief Disconnect an ISR from an interrupt line |
| * |
| * Interrupt line <irq> (exception #<irq>+16) is disconnected from its ISR and |
| * the latter is replaced by _irq_spurious(). irq_disable() should have |
| * been called before invoking this routine. |
| * |
| * @return N/A |
| */ |
| void _irq_disconnect(unsigned int irq) |
| { |
| _irq_handler_set(irq, _irq_spurious, NULL); |
| } |
| #endif /* CONFIG_SW_ISR_TABLE_DYNAMIC */ |