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/* irq.h
*
* This include file describe the data structure and the functions implemented
* by rtems to write interrupt handlers.
*
* Copyright (c) 2000 Canon Research Centre France SA.
* Emmanuel Raguet, mailto:raguet@crf.canon.fr
*
* The license and distribution terms for this file may be
* found in found in the file LICENSE in this distribution or at
* http://www.OARcorp.com/rtems/license.html.
*
*/
#ifndef _IRQ_H_
#define _IRQ_H_
#ifdef __cplusplus
extern "C" {
#endif
/*
* Include some preprocessor value also used by assember code
*/
#include <rtems.h>
extern void default_int_handler();
/*-------------------------------------------------------------------------+
| Constants
+--------------------------------------------------------------------------*/
/* enum of the possible interrupt sources */
typedef enum {
BSP_INT_1 = 0,
BSP_INT_2 = 1,
BSP_UART = 2,
BSP_MAX_INT = 3
} rtems_irq_symbolic_name;
/* define that can be useful (the values are just examples) */
#define INTMASK 0x01
#define VECTOR_TABLE 0x00
/*
* Type definition for RTEMS managed interrupts
*/
typedef unsigned char rtems_irq_level;
typedef unsigned char rtems_irq_trigger;
struct __rtems_irq_connect_data__; /* forward declaratiuon */
typedef void (*rtems_irq_hdl) (void);
typedef void (*rtems_irq_enable) (const struct __rtems_irq_connect_data__*);
typedef void (*rtems_irq_disable) (const struct __rtems_irq_connect_data__*);
typedef int (*rtems_irq_is_enabled) (const struct __rtems_irq_connect_data__*);
typedef struct __rtems_irq_connect_data__ {
/*
* IRQ line
*/
rtems_irq_symbolic_name name;
/*
* handler. See comment on handler properties below in function prototype.
*/
rtems_irq_hdl hdl;
/*
* function for enabling interrupts at device level (ONLY!).
* The BSP code will automatically enable it at i8259s level.
* RATIONALE : anyway such code has to exist in current driver code.
* It is usually called immediately AFTER connecting the interrupt handler.
* RTEMS may well need such a function when restoring normal interrupt
* processing after a debug session.
*
*/
rtems_irq_enable on;
/*
* function for disabling interrupts at device level (ONLY!).
* The code will disable it at i8259s level. RATIONALE : anyway
* such code has to exist for clean shutdown. It is usually called
* BEFORE disconnecting the interrupt. RTEMS may well need such
* a function when disabling normal interrupt processing for
* a debug session. May well be a NOP function.
*/
rtems_irq_disable off;
/*
* function enabling to know what interrupt may currently occur
* if someone manipulates the i8259s interrupt mask without care...
*/
rtems_irq_is_enabled isOn;
/*
* priority level at the vplus level
*/
rtems_irq_level irqLevel;
/*
* Trigger way : Rising or falling edge or High or low level
*/
rtems_irq_trigger irqTrigger;
} rtems_irq_connect_data;
/*-------------------------------------------------------------------------+
| Function Prototypes.
+--------------------------------------------------------------------------*/
/*
* ------------------------ RTEMS Single Irq Handler Mngt Routines ----------------
*/
/*
* function to initialize the interrupt for a specific BSP
*/
void BSP_rtems_irq_mngt_init();
/*
* function to connect a particular irq handler. This hanlder will NOT be called
* directly as the result of the corresponding interrupt. Instead, a RTEMS
* irq prologue will be called that will :
*
* 1) save the C scratch registers,
* 2) switch to a interrupt stack if the interrupt is not nested,
* 3) store the current i8259s' interrupt masks
* 4) modify them to disable the current interrupt at 8259 level (and may
* be others depending on software priorities)
* 5) aknowledge the i8259s',
* 6) demask the processor,
* 7) call the application handler
*
* As a result the hdl function provided
*
* a) can perfectly be written is C,
* b) may also well directly call the part of the RTEMS API that can be used
* from interrupt level,
* c) It only responsible for handling the jobs that need to be done at
* the device level including (aknowledging/re-enabling the interrupt at device,
* level, getting the data,...)
*
* When returning from the function, the following will be performed by
* the RTEMS irq epilogue :
*
* 1) masks the interrupts again,
* 2) restore the original i8259s' interrupt masks
* 3) switch back on the orinal stack if needed,
* 4) perform rescheduling when necessary,
* 5) restore the C scratch registers...
* 6) restore initial execution flow
*
*/
int BSP_install_rtems_irq_handler (const rtems_irq_connect_data*);
/*
* function to get the current RTEMS irq handler for ptr->name. It enables to
* define hanlder chain...
*/
int BSP_get_current_rtems_irq_handler (rtems_irq_connect_data* ptr);
/*
* function to get disconnect the RTEMS irq handler for ptr->name.
* This function checks that the value given is the current one for safety reason.
* The user can use the previous function to get it.
*/
int BSP_remove_rtems_irq_handler (const rtems_irq_connect_data*);
#ifdef __cplusplus
}
#endif
#endif /* _IRQ_H_ */
/* end of include file */
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