4 * This file is part of BeRTOS.
6 * Bertos is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
20 * As a special exception, you may use this file as part of a free software
21 * library without restriction. Specifically, if other files instantiate
22 * templates or use macros or inline functions from this file, or you compile
23 * this file and link it with other files to produce an executable, this
24 * file does not by itself cause the resulting executable to be covered by
25 * the GNU General Public License. This exception does not however
26 * invalidate any other reasons why the executable file might be covered by
27 * the GNU General Public License.
29 * Copyright 2007 Develer S.r.l. (http://www.develer.com/)
35 * \author Francesco Sacchi <batt@develer.com>
37 * \brief System IRQ handler for Atmel AT91 ARM7 processors.
39 * In Atmel AT91 ARM7TDMI processors, there are various
40 * peripheral interrupt sources.
41 * In general, every source has its own interrupt vector, so it
42 * is possible to assign a specific handler for each interrupt
44 * However, there are a few sources called "system sources" that
45 * share a common IRQ line and vector, called "system IRQ".
46 * So a unique system IRQ dispatcher is implemented here.
47 * This module also contains an interface to manage every source
48 * independently. It is possible to assign to every system IRQ
49 * a specific IRQ handler.
51 * \see sysirq_setHandler
52 * \see sysirq_setEnable
55 #include "sysirq_at91.h"
58 #include <cpu/types.h>
59 #include <cfg/module.h>
60 #include <cfg/macros.h>
63 * Enable/disable the Periodic Interrupt Timer
66 INLINE void pit_setEnable(bool enable)
71 PIT_MR &= ~BV(PITIEN);
75 * Table containing all system irqs.
77 static SysIrq sysirq_tab[] =
79 /* PIT, Periodic Interval Timer (System timer)*/
82 .setEnable = pit_setEnable,
85 /* TODO: add other system sources here */
88 STATIC_ASSERT(countof(sysirq_tab) == SYSIRQ_CNT);
91 * System IRQ dispatcher.
92 * This is the entry point for all system IRQs in AT91.
93 * This function checks for interrupt enable state of
94 * various sources (system timer, etc..) and calls
95 * the corresponding handler.
97 static void sysirq_dispatcher(void) __attribute__ ((naked));
98 static void sysirq_dispatcher(void)
103 if ((PIT_MR & BV(PITIEN))
104 && (PIT_SR & BV(PITS))
105 && sysirq_tab[SYSIRQ_PIT].handler)
106 sysirq_tab[SYSIRQ_PIT].handler();
108 /* TODO: add other system sources here */
113 #define SYSIRQ_PRIORITY 0 ///< default priority for system irqs.
119 * Init system IRQ handling.
120 * \note all system interrupts are disabled.
122 void sysirq_init(void)
125 IRQ_SAVE_DISABLE(flags);
127 /* Disable all system interrupts */
128 PIT_MR &= BV(PITIEN);
129 /* TODO: add other system sources here */
131 /* Set the vector. */
132 AIC_SVR(SYSC_ID) = sysirq_dispatcher;
133 /* Initialize to edge triggered with defined priority. */
134 AIC_SMR(SYSC_ID) = AIC_SRCTYPE_INT_EDGE_TRIGGERED | SYSIRQ_PRIORITY;
135 /* Clear pending interrupt */
136 AIC_ICCR = BV(SYSC_ID);
137 /* Enable the system IRQ */
138 AIC_IECR = BV(SYSC_ID);
146 * Helper function used to set handler for system IRQ \a irq.
148 void sysirq_setHandler(sysirq_t irq, sysirq_handler_t handler)
150 ASSERT(irq < SYSIRQ_CNT);
151 sysirq_tab[irq].handler = handler;
155 * Helper function used to enable/disable system IRQ \a irq.
157 void sysirq_setEnable(sysirq_t irq, bool enable)
159 ASSERT(irq < SYSIRQ_CNT);
161 sysirq_tab[irq].setEnable(enable);
162 sysirq_tab[irq].enabled = enable;
166 * Helper function used to get system IRQ \a irq state.
168 bool sysirq_enabled(sysirq_t irq)
170 ASSERT(irq < SYSIRQ_CNT);
172 return sysirq_tab[irq].enabled;