| /* |
| * Copyright (c) 2010, Swedish Institute of Computer Science. |
| * All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions |
| * are met: |
| * 1. Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * 2. 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. |
| * 3. Neither the name of the Institute nor the names of its contributors |
| * may be used to endorse or promote products derived from this software |
| * without specific prior written permission. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE 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 INSTITUTE 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. |
| * |
| */ |
| |
| /** |
| * \file |
| * Basic SPI macros |
| * \author |
| * Joakim Eriksson <joakime@sics.se> |
| * Niclas Finne <nfi@sics.se> |
| */ |
| |
| #ifndef SPI_H_ |
| #define SPI_H_ |
| |
| /* Define macros to use for checking SPI transmission status depending |
| on if it is possible to wait for TX buffer ready. This is possible |
| on for example MSP430 but not on AVR. */ |
| #ifdef SPI_WAITFORTxREADY |
| #define SPI_WAITFORTx_BEFORE() SPI_WAITFORTxREADY() |
| #define SPI_WAITFORTx_AFTER() |
| #define SPI_WAITFORTx_ENDED() SPI_WAITFOREOTx() |
| #else /* SPI_WAITFORTxREADY */ |
| #define SPI_WAITFORTx_BEFORE() |
| #define SPI_WAITFORTx_AFTER() SPI_WAITFOREOTx() |
| #define SPI_WAITFORTx_ENDED() |
| #endif /* SPI_WAITFORTxREADY */ |
| |
| extern unsigned char spi_busy; |
| |
| void spi_init(void); |
| |
| /* Write one character to SPI */ |
| #define SPI_WRITE(data) \ |
| do { \ |
| SPI_WAITFORTx_BEFORE(); \ |
| SPI_TXBUF = data; \ |
| SPI_WAITFOREOTx(); \ |
| } while(0) |
| |
| /* Write one character to SPI - will not wait for end |
| useful for multiple writes with wait after final */ |
| #define SPI_WRITE_FAST(data) \ |
| do { \ |
| SPI_WAITFORTx_BEFORE(); \ |
| SPI_TXBUF = data; \ |
| SPI_WAITFORTx_AFTER(); \ |
| } while(0) |
| |
| /* Read one character from SPI */ |
| #define SPI_READ(data) \ |
| do { \ |
| SPI_TXBUF = 0; \ |
| SPI_WAITFOREORx(); \ |
| data = SPI_RXBUF; \ |
| } while(0) |
| |
| /* Flush the SPI read register */ |
| #ifndef SPI_FLUSH |
| #define SPI_FLUSH() \ |
| do { \ |
| SPI_RXBUF; \ |
| } while(0); |
| #endif |
| |
| #endif /* SPI_H_ */ |
