/* irq.h
*
* This include file describe the data structure and the functions implemented
* by rtems to write interrupt handlers.
*
* CopyRight (C) 1998 valette@crf.canon.fr
*
* This code is heavilly inspired by the public specification of STREAM V2
* that can be found at :
*
* <http://www.chorus.com/Documentation/index.html> by following
* the STREAM API Specification Document link.
*
* 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.
*
* $Id$
*/
#ifndef _IRQ_H_
#define _IRQ_H_
#ifdef __cplusplus
extern "C" {
#endif
/*
* Include some preprocessor value also used by assember code
*/
#include <irq_asm.h>
#include <rtems.h>
/*-------------------------------------------------------------------------+
| Constants
+--------------------------------------------------------------------------*/
typedef enum {
/* Base vector for our IRQ handlers. */
PC386_IRQ_VECTOR_BASE = PC386_ASM_IRQ_VECTOR_BASE,
PC_386_IRQ_LINES_NUMBER = 16,
PC_386_LOWEST_OFFSET = 0,
PC_386_MAX_OFFSET = PC_386_IRQ_LINES_NUMBER - 1,
/*
* Interrupt offset in comparison to PC386_ASM_IRQ_VECTOR_BASE
* NB : 1) Interrupt vector number in IDT = offset + PC386_ASM_IRQ_VECTOR_BASE
* 2) The same name should be defined on all architecture
* so that handler connexion can be unchanged.
*/
PC_386_PERIODIC_TIMER = 0,
PC_386_KEYBOARD = 1,
PC386_UART_COM2_IRQ = 3,
PC386_UART_COM1_IRQ = 4,
PC_386_RT_TIMER1 = 8
}rtems_irq_symbolic_name;
/*
* Type definition for RTEMS managed interrupts
*/
typedef unsigned char rtems_irq_prio;
typedef unsigned short rtems_i8259_masks;
extern rtems_i8259_masks i8259s_cache;
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;
}rtems_irq_connect_data;
typedef struct {
/*
* size of all the table fields (*Tbl) described below.
*/
unsigned int irqNb;
/*
* Default handler used when disconnecting interrupts.
*/
rtems_irq_connect_data defaultEntry;
/*
* Table containing initials/current value.
*/
rtems_irq_connect_data* irqHdlTbl;
/*
* actual value of PC386_IRQ_VECTOR_BASE...
*/
rtems_irq_symbolic_name irqBase;
/*
* software priorities associated with interrupts.
* if irqPrio [i] > intrPrio [j] it means that
* interrupt handler hdl connected for interrupt name i
* will not be interrupted by the handler connected for interrupt j
* The interrupt source will be physically masked at i8259 level.
*/
rtems_irq_prio* irqPrioTbl;
}rtems_irq_global_settings;
/*-------------------------------------------------------------------------+
| Function Prototypes.
+--------------------------------------------------------------------------*/
/*
* ------------------------ Intel 8259 (or emulation) Mngt Routines -------
*/
/*
* function to disable a particular irq at 8259 level. After calling
* this function, even if the device asserts the interrupt line it will
* not be propagated further to the processor
*/
int pc386_irq_disable_at_i8259s (const rtems_irq_symbolic_name irqLine);
/*
* function to enable a particular irq at 8259 level. After calling
* this function, if the device asserts the interrupt line it will
* be propagated further to the processor
*/
int pc386_irq_enable_at_i8259s (const rtems_irq_symbolic_name irqLine);
/*
* function to acknoledge a particular irq at 8259 level. After calling
* this function, if a device asserts an enabled interrupt line it will
* be propagated further to the processor. Mainly usefull for people
* writting raw handlers as this is automagically done for rtems managed
* handlers.
*/
int pc386_irq_ack_at_i8259s (const rtems_irq_symbolic_name irqLine);
/*
* function to check if a particular irq is enabled at 8259 level. After calling
*/
int pc386_irq_enabled_at_i8259s (const rtems_irq_symbolic_name irqLine);
/*
* ------------------------ RTEMS Single Irq Handler Mngt Routines ----------------
*/
/*
* 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 pc386_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 pc386_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 pc386_remove_rtems_irq_handler (const rtems_irq_connect_data*);
/*
* ------------------------ RTEMS Global Irq Handler Mngt Routines ----------------
*/
/*
* (Re) Initialize the RTEMS interrupt management.
*
* The result of calling this function will be the same as if each individual
* handler (config->irqHdlTbl[i].hdl) different from "config->defaultEntry.hdl"
* has been individualy connected via
* pc386_install_rtems_irq_handler(&config->irqHdlTbl[i])
* And each handler currently equal to config->defaultEntry.hdl
* has been previously disconnected via
* pc386_remove_rtems_irq_handler (&config->irqHdlTbl[i])
*
* This is to say that all information given will be used and not just
* only the space.
*
* CAUTION : the various table address contained in config will be used
* directly by the interrupt mangement code in order to save
* data size so they must stay valid after the call => they should
* not be modified or declared on a stack.
*/
int pc386_rtems_irq_mngt_set(rtems_irq_global_settings* config);
/*
* (Re) get info on current RTEMS interrupt management.
*/
int pc386_rtems_irq_mngt_get(rtems_irq_global_settings**);
#ifdef __cplusplus
}
#endif
#endif /* _IRQ_H_ */
/* end of include file */
