80 lines
3.6 KiB
C
80 lines
3.6 KiB
C
/*****************************************************************************\
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* EFSL - Embedded Filesystems Library *
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* ----------------------------------- *
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* *
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* Filename : atmega_spi.c *
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* Release : 0.3 - devel *
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* Description : This file contains the functions needed to use efs for *
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* accessing files on an SD-card connected to an ATMega's. *
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* *
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* This program is free software; you can redistribute it and/or *
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* modify it under the terms of the GNU General Public License *
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* as published by the Free Software Foundation; version 2 *
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* of the License. *
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* *
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* This program is distributed in the hope that it will be useful, *
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* but WITHOUT ANY WARRANTY; without even the implied warranty of *
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the *
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* GNU General Public License for more details. *
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* *
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* As a special exception, if other files instantiate templates or *
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* use macros or inline functions from this file, or you compile this *
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* file and link it with other works to produce a work based on this file, *
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* this file does not by itself cause the resulting work to be covered *
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* by the GNU General Public License. However the source code for this *
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* file must still be made available in accordance with section (3) of *
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* the GNU General Public License. *
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* *
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* This exception does not invalidate any other reasons why a work based *
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* on this file might be covered by the GNU General Public License. *
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* *
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* (c)2006 Lennart Yseboodt *
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* (c)2006 Michael De Nil *
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\*****************************************************************************/
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/*****************************************************************************/
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#include "include/atmega_spi.h"
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/*****************************************************************************/
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euint8 atmega_spi_init(atmegaSpiInterface *iface)
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{
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euint8 i;
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/* Unselect card */
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PORTB |= iface->pinSelect;
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/* Set as master, clock and chip select output */
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DDR_SPI = (1<<DD_MOSI) | (1<<DD_SCK) | 1;
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/* Enable SPI, master, set clock rate to fck/2 */
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SPCR = (1<<SPE) | (1<<MSTR); /* fsck / 4 */
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SPSR = 1; /* fsck / 2 */
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/* Send 10 spi commands with card not selected */
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for(i=0;i<10;i++)
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atmega_spi_send(iface,0xff);
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/* Select card */
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PORTB &= ~(iface->pinSelect);
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return(0);
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}
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/*****************************************************************************/
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euint8 atmega_spi_send(atmegaSpiInterface *iface, euint8 data)
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{
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euint8 incoming=0;
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PORTB &= ~(iface->pinSelect);
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SPDR = data;
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while(!(SPSR & (1<<SPIF)))
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incoming = SPDR;
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PORTB |= iface->pinSelect;
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return(incoming);
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}
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/*****************************************************************************/
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