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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) 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: irq.h,v 1.2 2001-09-27 11:59:49 chris Exp $

 */

#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. */

  BSP_IRQ_VECTOR_BASE           =       BSP_ASM_IRQ_VECTOR_BASE,

  BSP_IRQ_LINES_NUMBER          =       16,

  BSP_LOWEST_OFFSET             =       0,

  BSP_MAX_OFFSET                =       BSP_IRQ_LINES_NUMBER - 1,

    /*

     * Interrupt offset in comparison to BSP_ASM_IRQ_VECTOR_BASE

     * NB : 1) Interrupt vector number in IDT = offset + BSP_ASM_IRQ_VECTOR_BASE

     *      2) The same name should be defined on all architecture

     *         so that handler connexion can be unchanged.

     */

  BSP_PERIODIC_TIMER            =       0,

  BSP_KEYBOARD                  =       1,

  BSP_UART_COM2_IRQ             =       3,

  BSP_UART_COM1_IRQ             =       4,

  BSP_RT_TIMER1         =       8,

  BSP_RT_TIMER3         =       10

} 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 BSP_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 BSP_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 BSP_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 BSP_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 BSP_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 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*);

/*

 * ------------------------ 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

 *      BSP_install_rtems_irq_handler(&config->irqHdlTbl[i])

 * And each handler currently equal to config->defaultEntry.hdl

 * has been previously disconnected via

 *       BSP_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 BSP_rtems_irq_mngt_set(rtems_irq_global_settings* config);

/*

 * (Re) get info on current RTEMS interrupt management.

 */

int BSP_rtems_irq_mngt_get(rtems_irq_global_settings**);

#ifdef __cplusplus

}

#endif

#endif /* _IRQ_H_ */

/* end of include file */