2013-04-11 02:10:10 -06:00
|
|
|
/*
|
|
|
|
|
* This file is part of the COMROGUE Operating System for Raspberry Pi
|
|
|
|
|
*
|
|
|
|
|
* Copyright (c) 2013, Eric J. Bowersox / Erbosoft Enterprises
|
|
|
|
|
* All rights reserved.
|
|
|
|
|
*
|
|
|
|
|
* This program is free for commercial and non-commercial use as long as the following conditions are
|
|
|
|
|
* adhered to.
|
|
|
|
|
*
|
|
|
|
|
* Copyright in this file remains Eric J. Bowersox and/or Erbosoft, and as such any copyright notices
|
|
|
|
|
* in the code are not to be removed.
|
|
|
|
|
*
|
|
|
|
|
* Redistribution and use in source and binary forms, with or without modification, are permitted
|
|
|
|
|
* provided that the following conditions are met:
|
|
|
|
|
*
|
|
|
|
|
* * Redistributions of source code must retain the above copyright notice, this list of conditions and
|
|
|
|
|
* the following disclaimer.
|
|
|
|
|
* * 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.
|
|
|
|
|
*
|
|
|
|
|
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND 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 COPYRIGHT HOLDER OR 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.
|
|
|
|
|
*
|
|
|
|
|
* "Raspberry Pi" is a trademark of the Raspberry Pi Foundation.
|
|
|
|
|
*/
|
2013-04-23 01:49:58 -06:00
|
|
|
#include <comrogue/internals/asm-macros.h>
|
|
|
|
|
|
2013-04-11 02:10:10 -06:00
|
|
|
.section ".text"
|
|
|
|
|
|
|
|
|
|
/*------------------------
|
|
|
|
|
* Low-level IO functions
|
|
|
|
|
*------------------------
|
|
|
|
|
*/
|
|
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* Writes a 32-bit word of data to a memory-mapped IO port.
|
|
|
|
|
*
|
|
|
|
|
* Parameters:
|
|
|
|
|
* - kaPort = Kernel address of the IO port to write to.
|
|
|
|
|
* - uiData = Data to be written.
|
|
|
|
|
*
|
|
|
|
|
* Returns:
|
|
|
|
|
* Nothing.
|
|
|
|
|
*
|
|
|
|
|
* Side effects:
|
|
|
|
|
* Writing to any given IO port may have arbitrary side effects.
|
|
|
|
|
*/
|
|
|
|
|
.globl llIOWriteK
|
|
|
|
|
llIOWriteK:
|
|
|
|
|
str r1,[r0]
|
|
|
|
|
bx lr
|
|
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* Reads a 32-bit word of data from a memory-mapped IO port.
|
|
|
|
|
*
|
|
|
|
|
* Parameters:
|
|
|
|
|
* - kaPort = Kernel address of the IO port we read from.
|
|
|
|
|
*
|
|
|
|
|
* Returns:
|
|
|
|
|
* The word of data read from the IO port.
|
|
|
|
|
*
|
|
|
|
|
* Side effects:
|
|
|
|
|
* Reading from any given IO port may have arbitrary side effects.
|
|
|
|
|
*/
|
|
|
|
|
.globl llIOReadK
|
|
|
|
|
llIOReadK:
|
|
|
|
|
ldr r0,[r0]
|
|
|
|
|
bx lr
|
|
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* Delays for a certain number of cycles, to allow an IO operation to work.
|
|
|
|
|
*
|
|
|
|
|
* Parameters:
|
|
|
|
|
* - uiTicks = The number of "ticks" to delay.
|
|
|
|
|
*
|
|
|
|
|
* Returns:
|
|
|
|
|
* Nothing.
|
|
|
|
|
*/
|
|
|
|
|
.globl llIODelay
|
|
|
|
|
llIODelay:
|
|
|
|
|
push {lr}
|
|
|
|
|
.delaytop:
|
|
|
|
|
nop
|
|
|
|
|
nop
|
|
|
|
|
bl .delayreturn
|
|
|
|
|
nop
|
|
|
|
|
nop
|
|
|
|
|
subs r0, r0, #1
|
|
|
|
|
bne .delaytop
|
|
|
|
|
pop {lr}
|
|
|
|
|
.delayreturn:
|
|
|
|
|
bx lr
|
