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/**
* @file
*
* @ingroup ClassicIO
*
* @brief Classic Input/Output Manager implementation.
*/
/*
* COPYRIGHT (c) 1989-2009.
* On-Line Applications Research Corporation (OAR).
*
* Copyright (c) 2009 embedded brains GmbH.
*
* The license and distribution terms for this file may be
* found in the file LICENSE in this distribution or at
* http://www.rtems.org/license/LICENSE.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <rtems/ioimpl.h>
#include <rtems/rtems/intr.h>
ISR_LOCK_DEFINE( , _IO_Driver_registration_lock, "IO Driver Registration" )
static inline bool rtems_io_is_empty_table(
const rtems_driver_address_table *table
)
{
return table->initialization_entry == NULL && table->open_entry == NULL;
}
static rtems_status_code rtems_io_obtain_major_number(
rtems_device_major_number *major
)
{
rtems_device_major_number n = _IO_Number_of_drivers;
rtems_device_major_number m = 0;
/* major is error checked by caller */
for ( m = 0; m < n; ++m ) {
rtems_driver_address_table *const table = _IO_Driver_address_table + m;
if ( rtems_io_is_empty_table( table ) )
break;
}
/* Assigns invalid value in case of failure */
*major = m;
if ( m != n )
return RTEMS_SUCCESSFUL;
return RTEMS_TOO_MANY;
}
rtems_status_code rtems_io_register_driver(
rtems_device_major_number major,
const rtems_driver_address_table *driver_table,
rtems_device_major_number *registered_major
)
{
rtems_device_major_number major_limit = _IO_Number_of_drivers;
ISR_lock_Context lock_context;
if ( rtems_interrupt_is_in_progress() )
return RTEMS_CALLED_FROM_ISR;
if ( registered_major == NULL )
return RTEMS_INVALID_ADDRESS;
/* Set it to an invalid value */
*registered_major = major_limit;
if ( driver_table == NULL )
return RTEMS_INVALID_ADDRESS;
if ( rtems_io_is_empty_table( driver_table ) )
return RTEMS_INVALID_ADDRESS;
if ( major >= major_limit )
return RTEMS_INVALID_NUMBER;
_IO_Driver_registration_acquire( &lock_context );
if ( major == 0 ) {
rtems_status_code sc = rtems_io_obtain_major_number( registered_major );
if ( sc != RTEMS_SUCCESSFUL ) {
_IO_Driver_registration_release( &lock_context );
return sc;
}
major = *registered_major;
} else {
rtems_driver_address_table *const table = _IO_Driver_address_table + major;
if ( !rtems_io_is_empty_table( table ) ) {
_IO_Driver_registration_release( &lock_context );
return RTEMS_RESOURCE_IN_USE;
}
*registered_major = major;
}
_IO_Driver_address_table [major] = *driver_table;
_IO_Driver_registration_release( &lock_context );
if ( _IO_All_drivers_initialized ) {
/* Other drivers have already been initialized, we initialize
* the driver directly.
*/
return rtems_io_initialize( major, 0, NULL );
} else {
/* The driver will be initialized together with all other drivers
* in a later stage by _IO_Initialize_all_drivers().
*/
return RTEMS_SUCCESSFUL;
}
}
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