AVR32 Interrupt Controller driver module.
Definition in file intc.c.
#include <avr32/io.h>
#include "compiler.h"
#include "preprocessor.h"
#include "intc.h"
Go to the source code of this file.
Defines | |
#define | DECL_INT_LINE_HANDLER_TABLE(GRP, unused) static volatile __int_handler _int_line_handler_table_##GRP[Max(AVR32_INTC_NUM_IRQS_PER_GRP##GRP, 1)]; |
Creates a table of interrupt line handlers per interrupt group in order to optimize RAM space. | |
#define | INSERT_INT_LINE_HANDLER_TABLE(GRP, unused) {AVR32_INTC_NUM_IRQS_PER_GRP##GRP, _int_line_handler_table_##GRP}, |
Functions | |
__int_handler | _get_interrupt_handler (unsigned int int_lev) |
Gets the interrupt handler of the current event at the int_lev interrupt priority level (called from exception.S). | |
static void | _unhandled_interrupt (void) |
Default interrupt handler. | |
void | INTC_init_interrupts (void) |
Initializes the hardware interrupt controller driver. | |
void | INTC_register_interrupt (__int_handler handler, unsigned int irq, unsigned int int_lev) |
Registers an interrupt handler. | |
MREPEAT (AVR32_INTC_NUM_INT_GRPS, DECL_INT_LINE_HANDLER_TABLE,~) | |
Variables | |
struct { | |
volatile __int_handler * _int_line_handler_table | |
unsigned int num_irqs | |
} | _int_handler_table [AVR32_INTC_NUM_INT_GRPS] |
Table containing for each interrupt group the number of interrupt request lines and a pointer to the table of interrupt line handlers. | |
const unsigned int | ipr_val [AVR32_INTC_NUM_INT_LEVELS] |
Values to store in the interrupt priority registers for the various interrupt priority levels. |
#define DECL_INT_LINE_HANDLER_TABLE | ( | GRP, | |||
unused | ) | static volatile __int_handler _int_line_handler_table_##GRP[Max(AVR32_INTC_NUM_IRQS_PER_GRP##GRP, 1)]; |
#define INSERT_INT_LINE_HANDLER_TABLE | ( | GRP, | |||
unused | ) | {AVR32_INTC_NUM_IRQS_PER_GRP##GRP, _int_line_handler_table_##GRP}, |
__int_handler _get_interrupt_handler | ( | unsigned int | int_lev | ) |
Gets the interrupt handler of the current event at the int_lev interrupt priority level (called from exception.S).
int_lev | Interrupt priority level to handle. |
Definition at line 106 of file intc.c.
References _int_handler_table.
00107 { 00108 // ICR3 is mapped first, ICR0 last. 00109 // Code in exception.S puts int_lev in R12 which is used by AVR32-GCC to pass 00110 // a single argument to a function. 00111 unsigned int int_grp = AVR32_INTC.icr[AVR32_INTC_INT3 - int_lev]; 00112 unsigned int int_req = AVR32_INTC.irr[int_grp]; 00113 00114 // As an interrupt may disappear while it is being fetched by the CPU 00115 // (spurious interrupt caused by a delayed response from an MCU peripheral to 00116 // an interrupt flag clear or interrupt disable instruction), check if there 00117 // are remaining interrupt lines to process. 00118 // If a spurious interrupt occurs, the status register (SR) contains an 00119 // execution mode and interrupt level masks corresponding to a level 0 00120 // interrupt, whatever the interrupt priority level causing the spurious 00121 // event. This behavior has been chosen because a spurious interrupt has not 00122 // to be a priority one and because it may not cause any trouble to other 00123 // interrupts. 00124 // However, these spurious interrupts place the hardware in an unstable state 00125 // and could give problems in other/future versions of the CPU, so the 00126 // software has to be written so that they never occur. The only safe way of 00127 // achieving this is to always clear or disable peripheral interrupts with the 00128 // following sequence: 00129 // 1: Mask the interrupt in the CPU by setting GM (or IxM) in SR. 00130 // 2: Perform the bus access to the peripheral register that clears or 00131 // disables the interrupt. 00132 // 3: Wait until the interrupt has actually been cleared or disabled by the 00133 // peripheral. This is usually performed by reading from a register in the 00134 // same peripheral (it DOES NOT have to be the same register that was 00135 // accessed in step 2, but it MUST be in the same peripheral), what takes 00136 // bus system latencies into account, but peripheral internal latencies 00137 // (generally 0 cycle) also have to be considered. 00138 // 4: Unmask the interrupt in the CPU by clearing GM (or IxM) in SR. 00139 // Note that steps 1 and 4 are useless inside interrupt handlers as the 00140 // corresponding interrupt level is automatically masked by IxM (unless IxM is 00141 // explicitly cleared by the software). 00142 // 00143 // Get the right IRQ handler. 00144 // 00145 // If several interrupt lines are active in the group, the interrupt line with 00146 // the highest number is selected. This is to be coherent with the 00147 // prioritization of interrupt groups performed by the hardware interrupt 00148 // controller. 00149 // 00150 // If no handler has been registered for the pending interrupt, 00151 // _unhandled_interrupt will be selected thanks to the initialization of 00152 // _int_line_handler_table_x by INTC_init_interrupts. 00153 // 00154 // exception.S will provide the interrupt handler with a clean interrupt stack 00155 // frame, with nothing more pushed onto the stack. The interrupt handler must 00156 // manage the `rete' instruction, what can be done thanks to pure assembly, 00157 // inline assembly or the `__attribute__((__interrupt__))' C function 00158 // attribute. 00159 return (int_req) ? _int_handler_table[int_grp]._int_line_handler_table[32 - clz(int_req) - 1] : NULL; 00160 }
static void _unhandled_interrupt | ( | void | ) | [static] |
Default interrupt handler.
Definition at line 90 of file intc.c.
Referenced by INTC_init_interrupts().
void INTC_init_interrupts | ( | void | ) |
Initializes the hardware interrupt controller driver.
Definition at line 163 of file intc.c.
References _int_handler_table, _unhandled_interrupt(), and ipr_val.
Referenced by main().
00164 { 00165 unsigned int int_grp, int_req; 00166 00167 // For all interrupt groups, 00168 for (int_grp = 0; int_grp < AVR32_INTC_NUM_INT_GRPS; int_grp++) 00169 { 00170 // For all interrupt request lines of each group, 00171 for (int_req = 0; int_req < _int_handler_table[int_grp].num_irqs; int_req++) 00172 { 00173 // Assign _unhandled_interrupt as default interrupt handler. 00174 _int_handler_table[int_grp]._int_line_handler_table[int_req] = &_unhandled_interrupt; 00175 } 00176 00177 // Set the interrupt group priority register to its default value. 00178 // By default, all interrupt groups are linked to the interrupt priority 00179 // level 0 and to the interrupt vector _int0. 00180 AVR32_INTC.ipr[int_grp] = ipr_val[AVR32_INTC_INT0]; 00181 } 00182 }
void INTC_register_interrupt | ( | __int_handler | handler, | |
unsigned int | irq, | |||
unsigned int | int_lev | |||
) |
Registers an interrupt handler.
handler | Interrupt handler to register. | |
irq | IRQ of the interrupt handler to register. | |
int_lev | Interrupt priority level to assign to the group of this IRQ. |
If several interrupt handlers of a same group are registered with different priority levels, only the latest priority level set will be effective.
Definition at line 185 of file intc.c.
References _int_handler_table, AVR32_INTC_MAX_NUM_IRQS_PER_GRP, and ipr_val.
Referenced by main().
00186 { 00187 // Determine the group of the IRQ. 00188 unsigned int int_grp = irq / AVR32_INTC_MAX_NUM_IRQS_PER_GRP; 00189 00190 // Store in _int_line_handler_table_x the pointer to the interrupt handler, so 00191 // that _get_interrupt_handler can retrieve it when the interrupt is vectored. 00192 _int_handler_table[int_grp]._int_line_handler_table[irq % AVR32_INTC_MAX_NUM_IRQS_PER_GRP] = handler; 00193 00194 // Program the corresponding IPRX register to set the interrupt priority level 00195 // and the interrupt vector offset that will be fetched by the core interrupt 00196 // system. 00197 // NOTE: The _intx functions are intermediate assembly functions between the 00198 // core interrupt system and the user interrupt handler. 00199 AVR32_INTC.ipr[int_grp] = ipr_val[int_lev & (AVR32_INTC_IPR_INTLEVEL_MASK >> AVR32_INTC_IPR_INTLEVEL_OFFSET)]; 00200 }
MREPEAT | ( | AVR32_INTC_NUM_INT_GRPS | , | |
DECL_INT_LINE_HANDLER_TABLE | , | |||
~ | ||||
) |
struct { ... } _int_handler_table[AVR32_INTC_NUM_INT_GRPS] [static] |
Table containing for each interrupt group the number of interrupt request lines and a pointer to the table of interrupt line handlers.
Referenced by _get_interrupt_handler(), INTC_init_interrupts(), and INTC_register_interrupt().
volatile __int_handler* _int_line_handler_table |
const unsigned int ipr_val[AVR32_INTC_NUM_INT_LEVELS] |
Values to store in the interrupt priority registers for the various interrupt priority levels.
Referenced by INTC_init_interrupts(), and INTC_register_interrupt().