00001 /* This source file is part of the ATMEL AVR-UC3-SoftwareFramework-1.7.0 Release */ 00002 00003 /*This file is prepared for Doxygen automatic documentation generation.*/ 00019 /* Copyright (c) 2009 Atmel Corporation. All rights reserved. 00020 * 00021 * Redistribution and use in source and binary forms, with or without 00022 * modification, are permitted provided that the following conditions are met: 00023 * 00024 * 1. Redistributions of source code must retain the above copyright notice, this 00025 * list of conditions and the following disclaimer. 00026 * 00027 * 2. Redistributions in binary form must reproduce the above copyright notice, 00028 * this list of conditions and the following disclaimer in the documentation 00029 * and/or other materials provided with the distribution. 00030 * 00031 * 3. The name of Atmel may not be used to endorse or promote products derived 00032 * from this software without specific prior written permission. 00033 * 00034 * 4. This software may only be redistributed and used in connection with an Atmel 00035 * AVR product. 00036 * 00037 * THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR IMPLIED 00038 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 00039 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT ARE 00040 * EXPRESSLY AND SPECIFICALLY DISCLAIMED. IN NO EVENT SHALL ATMEL BE LIABLE FOR 00041 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES 00042 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 00043 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND 00044 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 00045 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS 00046 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE 00047 * 00048 */ 00049 00050 #include <arch/avr32.h> 00051 #include <dev/irqreg.h> 00052 #include <avr32/io.h> 00053 #include <arch/avr32/preprocessor.h> 00054 00055 /**************************** Added for NutOS ****************************/ 00056 00058 #define AVR32_INTC_MAX_NUM_IRQS_PER_GRP 32 00059 00061 #define AVR32_INTC_NUM_INT_LEVELS (1 << AVR32_INTC_IPR_INTLEVEL_SIZE) 00062 00064 typedef void (*__int_handler)(void); 00065 00066 #define Max(a, b) (((a) > (b)) ? (a) : (b)) 00067 00068 /*************************************************************************/ 00069 00070 // define _evba from exception.S 00071 extern void _evba; 00072 00074 extern const unsigned int ipr_val[AVR32_INTC_NUM_INT_LEVELS]; 00075 00078 #if (defined __GNUC__) 00079 #define DECL_INT_LINE_HANDLER_TABLE(GRP, unused) \ 00080 static volatile __int_handler _int_line_handler_table_##GRP[Max(AVR32_INTC_NUM_IRQS_PER_GRP##GRP, 1)]; 00081 #elif (defined __ICCAVR32__) 00082 #define DECL_INT_LINE_HANDLER_TABLE(GRP, unused) \ 00083 static volatile __no_init __int_handler _int_line_handler_table_##GRP[Max(AVR32_INTC_NUM_IRQS_PER_GRP##GRP, 1)]; 00084 #endif 00085 MREPEAT(AVR32_INTC_NUM_INT_GRPS, DECL_INT_LINE_HANDLER_TABLE, ~); 00086 #undef DECL_INT_LINE_HANDLER_TABLE 00087 00090 static const struct 00091 { 00092 unsigned int num_irqs; 00093 volatile __int_handler *_int_line_handler_table; 00094 } _int_handler_table[AVR32_INTC_NUM_INT_GRPS] = 00095 { 00096 #define INSERT_INT_LINE_HANDLER_TABLE(GRP, unused) \ 00097 {AVR32_INTC_NUM_IRQS_PER_GRP##GRP, _int_line_handler_table_##GRP}, 00098 MREPEAT(AVR32_INTC_NUM_INT_GRPS, INSERT_INT_LINE_HANDLER_TABLE, ~) 00099 #undef INSERT_INT_LINE_HANDLER_TABLE 00100 }; 00105 static SIGNAL(_unhandled_interrupt) 00106 { 00107 // Catch unregistered interrupts. 00108 while (1); 00109 } 00110 00111 00121 __int_handler _get_interrupt_handler(unsigned int int_level) 00122 { 00123 // ICR3 is mapped first, ICR0 last. 00124 // Code in exception.S puts int_level in R12 which is used by AVR32-GCC to 00125 // pass a single argument to a function. 00126 unsigned int int_grp = AVR32_INTC.icr[AVR32_INTC_INT3 - int_level]; 00127 unsigned int int_req = AVR32_INTC.irr[int_grp]; 00128 00129 // As an interrupt may disappear while it is being fetched by the CPU 00130 // (spurious interrupt caused by a delayed response from an MCU peripheral to 00131 // an interrupt flag clear or interrupt disable instruction), check if there 00132 // are remaining interrupt lines to process. 00133 // If a spurious interrupt occurs, the status register (SR) contains an 00134 // execution mode and interrupt level masks corresponding to a level 0 00135 // interrupt, whatever the interrupt priority level causing the spurious 00136 // event. This behavior has been chosen because a spurious interrupt has not 00137 // to be a priority one and because it may not cause any trouble to other 00138 // interrupts. 00139 // However, these spurious interrupts place the hardware in an unstable state 00140 // and could give problems in other/future versions of the CPU, so the 00141 // software has to be written so that they never occur. The only safe way of 00142 // achieving this is to always clear or disable peripheral interrupts with the 00143 // following sequence: 00144 // 1: Mask the interrupt in the CPU by setting GM (or IxM) in SR. 00145 // 2: Perform the bus access to the peripheral register that clears or 00146 // disables the interrupt. 00147 // 3: Wait until the interrupt has actually been cleared or disabled by the 00148 // peripheral. This is usually performed by reading from a register in the 00149 // same peripheral (it DOES NOT have to be the same register that was 00150 // accessed in step 2, but it MUST be in the same peripheral), what takes 00151 // bus system latencies into account, but peripheral internal latencies 00152 // (generally 0 cycle) also have to be considered. 00153 // 4: Unmask the interrupt in the CPU by clearing GM (or IxM) in SR. 00154 // Note that steps 1 and 4 are useless inside interrupt handlers as the 00155 // corresponding interrupt level is automatically masked by IxM (unless IxM is 00156 // explicitly cleared by the software). 00157 // 00158 // Get the right IRQ handler. 00159 // 00160 // If several interrupt lines are active in the group, the interrupt line with 00161 // the highest number is selected. This is to be coherent with the 00162 // prioritization of interrupt groups performed by the hardware interrupt 00163 // controller. 00164 // 00165 // If no handler has been registered for the pending interrupt, 00166 // _unhandled_interrupt will be selected thanks to the initialization of 00167 // _int_line_handler_table_x by INTC_init_interrupts. 00168 // 00169 // exception.S will provide the interrupt handler with a clean interrupt stack 00170 // frame, with nothing more pushed onto the stack. The interrupt handler must 00171 // manage the `rete' instruction, what can be done thanks to pure assembly, 00172 // inline assembly or the `__attribute__((__interrupt__))' C function 00173 // attribute. 00174 return (int_req) ? _int_handler_table[int_grp]._int_line_handler_table[32 - __builtin_clz(int_req) - 1] : NULL; 00175 } 00176 00178 static __inline__ void INTC_init_evba(void) 00179 { 00180 Set_system_register(AVR32_EVBA, (int)&_evba ); 00181 } 00182 00183 void init_interrupts(void) 00184 { 00185 unsigned int int_grp, int_req; 00186 00187 INTC_init_evba(); 00188 00189 // For all interrupt groups, 00190 for (int_grp = 0; int_grp < AVR32_INTC_NUM_INT_GRPS; int_grp++) 00191 { 00192 // For all interrupt request lines of each group, 00193 for (int_req = 0; int_req < _int_handler_table[int_grp].num_irqs; int_req++) 00194 { 00195 // Assign _unhandled_interrupt as default interrupt handler. 00196 _int_handler_table[int_grp]._int_line_handler_table[int_req] = &_unhandled_interrupt; 00197 } 00198 00199 // Set the interrupt group priority register to its default value. 00200 // By default, all interrupt groups are linked to the interrupt priority 00201 // level 0 and to the interrupt vector _int0. 00202 AVR32_INTC.ipr[int_grp] = ipr_val[AVR32_INTC_INT0]; 00203 } 00204 } 00205 00206 00207 void register_interrupt(__int_handler handler, unsigned int irq, unsigned int int_level) 00208 { 00209 // Determine the group of the IRQ. 00210 unsigned int int_grp = irq / AVR32_INTC_MAX_NUM_IRQS_PER_GRP; 00211 00212 // Store in _int_line_handler_table_x the pointer to the interrupt handler, so 00213 // that _get_interrupt_handler can retrieve it when the interrupt is vectored. 00214 _int_handler_table[int_grp]._int_line_handler_table[irq % AVR32_INTC_MAX_NUM_IRQS_PER_GRP] = handler; 00215 00216 // Program the corresponding IPRX register to set the interrupt priority level 00217 // and the interrupt vector offset that will be fetched by the core interrupt 00218 // system. 00219 // NOTE: The _intx functions are intermediate assembly functions between the 00220 // core interrupt system and the user interrupt handler. 00221 AVR32_INTC.ipr[int_grp] = ipr_val[int_level & (AVR32_INTC_IPR_INTLEVEL_MASK >> AVR32_INTC_IPR_INTLEVEL_OFFSET)]; 00222 }