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/*! \file spi.c \brief SPI interface driver. */
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//*****************************************************************************
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//
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// File Name : 'spi.c'
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// Title : SPI interface driver
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// Author : Pascal Stang - Copyright (C) 2000-2002
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// Created : 11/22/2000
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// Revised : 06/06/2002
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// Version : 0.6
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// Target MCU : Atmel AVR series
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// Editor Tabs : 4
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//
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// NOTE: This code is currently below version 1.0, and therefore is considered
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// to be lacking in some functionality or documentation, or may not be fully
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// tested. Nonetheless, you can expect most functions to work.
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//
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// ----------------------------------------------------------------------------
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// 17.8.2008
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// Bob!k & Raster, C.P.U.
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// Original code was modified especially for the SDrive device.
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// Some parts of code have been added, removed, rewrited or optimized due to
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// lack of MCU AVR Atmega8 memory.
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// ----------------------------------------------------------------------------
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//
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// This code is distributed under the GNU Public License
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// which can be found at http://www.gnu.org/licenses/gpl.txt
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//
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//*****************************************************************************
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#include "spi.h"
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#include "regs.h"
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#include "spi.h"
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int spi_slow; // 1 is slow
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int spi_chip_select_n; // 0 is selected
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int display;
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void updateSpiState()
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{
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*zpu_spi_state = (spi_slow<<1)|(spi_chip_select_n);
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}
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// access routines
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void setSpiFast()
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{
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spi_slow = 0;
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updateSpiState();
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}
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void setSpiSlow()
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{
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spi_slow = 1;
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updateSpiState();
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}
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void set_spi_clock_freq() // avr handles spi clock?
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{
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setSpiFast();
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}
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void spiInit()
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{
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spiDisplay(0);
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spi_slow = 1;
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spi_chip_select_n = 1;
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updateSpiState();
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}
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void mmcChipSelect(int select)
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{
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spi_chip_select_n = !select;
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updateSpiState();
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}
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u08 spiTransferByte(u08 data)
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{
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u08 res = 0;
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//debug("spiTransferByte");
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/*if (display!=0)
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{
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plotnext(hextoatarichar((data&0xf0) >> 4));
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plotnext(hextoatarichar((data&0xf)));
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}*/
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// send the given data
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*zpu_spi_data = data;
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// wait for transfer to complete
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while ((1&*zpu_spi_state) == 1);
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// return the received data
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res = *zpu_spi_data;
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if (display!=0)
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{
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plotnext(hextoatarichar((res&0xf0) >> 4));
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plotnext(hextoatarichar((res&0xf)));
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//plotnext(toatarichar(' '));
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}
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return res;
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}
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u08 spiTransferFF()
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{
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return spiTransferByte(0xFF);
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}
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void spiDisplay(int i)
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{
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display = i;
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}
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