mirror of
git://projects.qi-hardware.com/ben-wpan.git
synced 2024-11-23 00:58:26 +02:00
ec7c93789a
- spi.h (spi_off), spi.c: disable the UART - spi.c (spi_initialized, spi_begin, spi_init): initialize the UART if necessary - board_app.c (gpio): call spi_off to disable the UART instead of open-coding the operation - board_app.c (gpio): don't explicitly re-enable the UART but defer it to the next communication
73 lines
1.2 KiB
C
73 lines
1.2 KiB
C
/*
|
|
* fw/spi.c - ATmega8 family SPI I/O
|
|
*
|
|
* Written 2011 by Werner Almesberger
|
|
* Copyright 2011 Werner Almesberger
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License as published by
|
|
* the Free Software Foundation; either version 2 of the License, or
|
|
* (at your option) any later version.
|
|
*/
|
|
|
|
|
|
#include <stdint.h>
|
|
|
|
#include <avr/io.h>
|
|
|
|
#include "board.h"
|
|
#include "spi.h"
|
|
|
|
|
|
static int spi_initialized = 0;
|
|
|
|
|
|
void spi_begin(void)
|
|
{
|
|
if (!spi_initialized)
|
|
spi_init();
|
|
CLR(nSS);
|
|
}
|
|
|
|
|
|
uint8_t spi_io(uint8_t v)
|
|
{
|
|
// while (!(UCSR1A & 1 << UDRE1));
|
|
UDR1 = v;
|
|
while (!(UCSR1A & 1 << RXC1));
|
|
return UDR1;
|
|
}
|
|
|
|
|
|
void spi_end(void)
|
|
{
|
|
// while (!(UCSR1A & 1 << TXC1));
|
|
SET(nSS);
|
|
}
|
|
|
|
|
|
void spi_off(void)
|
|
{
|
|
spi_initialized = 0;
|
|
UCSR1B = 0;
|
|
}
|
|
|
|
|
|
void spi_init(void)
|
|
{
|
|
SET(nSS);
|
|
OUT(SCLK);
|
|
OUT(MOSI);
|
|
OUT(nSS);
|
|
IN(MISO);
|
|
|
|
UBRR1 = 0; /* set bit rate to zero to begin */
|
|
UCSR1C = 1 << UMSEL11 | 1 << UMSEL10;
|
|
/* set MSPI, MSB first, SPI data mode 0 */
|
|
UCSR1B = 1 << RXEN1 | 1 << TXEN1;
|
|
/* enable receiver and transmitter */
|
|
UBRR1 = 0; /* reconfirm the bit rate */
|
|
|
|
spi_initialized = 1;
|
|
}
|