/* spi.avr.c */ /* avr.spi - SPI AVR module. {{{ * * Copyright (C) 2008 NĂ©lio Laranjeiro * * APBTeam: * Web: http://apbteam.org/ * Email: team AT apbteam DOT org * * 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. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. * * }}} */ #include "common.h" #include "io.h" #include "spi.h" /** Initialise the SPI Control Register. * \param spcr the spcr register data to be store in the register. */ void spi_init (uint8_t spcr) { /* Master configuration. */ if (spcr & _BV(MSTR)) { SPI_PORT |= _BV(SPI_BIT_SS); SPI_DDR |= _BV(SPI_BIT_SS); SPI_DDR &= ~_BV(SPI_BIT_MISO); SPI_PORT &= ~_BV(SPI_BIT_MISO); SPI_PORT |= _BV(SPI_BIT_MOSI); SPI_DDR |= _BV(SPI_BIT_MOSI); SPI_PORT |= _BV(SPI_BIT_SCK); SPI_DDR |= _BV(SPI_BIT_SCK); } else { SPI_DDR &= ~_BV(SPI_BIT_SS); SPI_PORT |= _BV(SPI_BIT_SS); SPI_PORT |= _BV(SPI_BIT_MISO); SPI_DDR |= _BV(SPI_BIT_MISO); SPI_DDR &= ~_BV(SPI_BIT_MOSI); SPI_PORT &= ~_BV(SPI_BIT_MOSI); SPI_DDR &= ~_BV(SPI_BIT_SCK); SPI_PORT &= ~_BV(SPI_BIT_SCK); } SPCR = spcr; } /** Send a data to the Slave. * \param data the data to send */ void spi_send (uint8_t data) { spi_send_and_recv (data); } /** Receive a data from the SPI bus. * \return the data received from the bus. */ uint8_t spi_recv (void) { return spi_send_and_recv (0); } /** Send and receive data. * \param data the data to send. * \return the data received. */ uint8_t spi_send_and_recv (uint8_t data) { SPDR = data; /* Wait the end of the transmission. */ while (!(SPSR & _BV(SPIF))) ; /* Return data register. */ return SPDR; }