ddf_io.c

ARM嵌入式系统开发--软件设计与优化随书源代码。开发环境asm+c

/*
 *  ____________________________________________________________________
 * 
 *  Copyright (c) 2002, Andrew N. Sloss, Chris Wright and Dominic Symes
 *  All rights reserved.
 *  ____________________________________________________________________
 * 
 *  NON-COMMERCIAL USE License
 *  
 *  Redistribution and use in source and binary forms, with or without 
 *  modification, are permitted provided that the following conditions 
 *  are met: 
 *  
 *  1. For NON-COMMERCIAL USE only.
 * 
 *  2. Redistributions of source code must retain the above copyright 
 *     notice, this list of conditions and the following disclaimer. 
 * 
 *  3. Redistributions in binary form must reproduce the above 
 *     copyright notice, this list of conditions and the following 
 *     disclaimer in the documentation and/or other materials provided 
 *     with the distribution. 
 * 
 *  4. All advertising materials mentioning features or use of this 
 *     software must display the following acknowledgement:
 * 
 *     This product includes software developed by Andrew N. Sloss,
 *     Chris Wright and Dominic Symes. 
 * 
 *   THIS SOFTWARE IS PROVIDED BY THE CONTRIBUTORS ``AS IS'' AND ANY 
 *   EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 
 *   IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 
 *   PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE CONTRIBUTORS BE 
 *   LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, 
 *   OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, 
 *   PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, 
 *   OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 
 *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR 
 *   TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT 
 *   OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY 
 *   OF SUCH DAMAGE. 
 * 
 *  If you have questions about this license or would like a different
 *  license please email :
 * 
 * 	[e-mail]
 * 
 * 
 */
 
/*****************************************************************************
 * Simple Little Operating System - mmuSLOS
 *****************************************************************************/

/*****************************************************************************
 * 
 * Module       : io.c
 * Description  : interface to the low level drivers. io conform
 *                with DDF 0.01 specification.
 * OS           : mmuSLOS 0.03
 * Platform     : cm920iap
 * History      :
 *
 * 20th November 2001 Andrew N. Sloss
 * - created io.c from the DDF 0.01 test program
 *
 *****************************************************************************/

/*****************************************************************************
 * IMPORT 
 *****************************************************************************/

#include "../cm920iap/devices/tree.h"

/***********************************************************************
 * ROUTINES 
 ***********************************************************************/

/* -- io_initalize_drivers ---------------------------------------------------
 *
 * Description : initializes all the device driver in the device_treestr
 *
 * Parameters  : DDF does not take any parameter
 * Return      : none...
 * Notes       :
 * 
 */

void io_initialize_drivers(void) 
{
device_treestr *driver = devices;

  while (*driver->init != 0) 
  {
  driver->init();
  driver ++;
  }
}

/* -- io_open_driver --------------------------------------------------------
 * 
 * Description : open a driver for access
 *
 * Parameters  : int *id - pointer the id 
 *             : unsigned major - major device i.e. DEVICE_SERIAL_E7T
 *             : unsigned minor - minor device i.e. COM1
 * Return      : device_treestr * ptr
 * Notes       :
 *
 */ 

device_treestr *io_open_driver(int *id,unsigned major,unsigned minor) 
{
device_treestr *driver = devices;

  while (*driver->init != 0) 
  {
  *id = driver->open(major,minor);  	

    if (*id>0) 
    {
    return driver;
    }

  driver ++;
  }

return (device_treestr *)0; /* no driver found */
}

/* -- io_open_driver --------------------------------------------------------
 * 
 * Description : open a driver for access
 *
 * Parameters  : device_treestr * - pointer to device node. 
 *             : UID id - id of particular device
 * Return      : int 
 * Notes       : 
 *
 */ 

int io_close_driver(device_treestr *d, UID id) 
{
  if (d==(device_treestr *)0) {return -2;}

  return d->close (id);
}

/* -- io_bit_write ----------------------------------------------------------
 * 
 * Description : write a bit to the device
 *
 * Parameters  : device_treestr * - pointer to device node. 
 *             : UID id - id of particular device
 *             : BYTE bit - only least significant used
 * Return      : none...
 * Notes       : 
 *
 */ 

void io_write_bit(device_treestr *d,UID id,BYTE bit) 
{
  if (d==(device_treestr *)0) {return;}

  d->write.bit (id,bit);
}

/* -- io_bit_read -----------------------------------------------------------
 * 
 * Description : write a bit to the device
 *
 * Parameters  : device_treestr * - pointer to device node. 
 *             : UID id - id of particular device
 *             : BYTE bit - only least significant used
 * Return      : BYTE if = 255 then error
 * Notes       : 
 *
 */ 

BYTE io_read_bit(device_treestr *d,UID id) 
{
  if (d==(device_treestr *)0) {return 255;}

  return d->read.bit (id);
}

/* -- io_write_byte ---------------------------------------------------------
 * 
 * Description : write a bit to the device
 *
 * Parameters  : device_treestr * - pointer to device node. 
 *             : UID id - id of particular device
 *             : BYTE bit - only least significant used
 * Return      : none...
 * Notes       : 
 *
 */ 

void io_write_byte(device_treestr *d,UID id,BYTE bit) 
{
  if (d==(device_treestr *)0) {return;}

  d->write.byte (id,bit);
}

/* -- io_bit_read -----------------------------------------------------------
 * 
 * Description : write a bit to the device
 *
 * Parameters  : device_treestr * - pointer to device node. 
 *             : UID id - id of particular device
 *             : BYTE bit - only least significant used
 * Return      : BYTE if = 255 then error
 * Notes       : 
 *
 */ 

BYTE io_read_byte(device_treestr *d,UID id) 
{
  if (d==(device_treestr *)0) {return 255;}

  return d->read.byte (id);
}

/* -- io_bit_write ----------------------------------------------------------
 * 
 * Description : write a bit to the device
 *
 * Parameters  : device_treestr * - pointer to device node. 
 *             : UID id - id of particular device
 *             : BYTE bit - only least significant used
 * Return      : none...
 * Notes       : 
 *
 */ 

void io_write_block(device_treestr *d,UID id, block_datastr *block) 
{
  if (d==(device_treestr *)0) {return;}

  d->write.block (id,block);
}

/* -- io_bit_read -----------------------------------------------------------
 * 
 * Description : write a bit to the device
 *
 * Parameters  : device_treestr * - pointer to device node. 
 *             : UID id - id of particular device
 *             : BYTE bit - only least significant used
 * Return      : BYTE if = 255 then error
 * Notes       : 
 *
 */ 

block_datastr *io_read_block(device_treestr *d,UID id) 
{
  if (d==(device_treestr *)0) {return 0;}

  return d->read.block (id);
}