68 lines
2.6 KiB
C
68 lines
2.6 KiB
C
/*
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* Copyright (c) 2006, Swedish Institute of Computer Science
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. Neither the name of the Institute nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* @(#)$Id: spi.c,v 1.1 2006/06/17 22:41:21 adamdunkels Exp $
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*/
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#include "contiki-conf.h"
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/*
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* On the Tmote sky access to I2C/SPI/UART0 must always be
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* exclusive. Set spi_busy so that interrupt handlers can check if
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* they are allowed to use the bus or not. Only the CC2420 radio needs
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* this in practice.
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*
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*/
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unsigned char spi_busy = 0;
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/*
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* Initialize SPI bus.
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*/
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void
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spi_init(void)
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{
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static unsigned char spi_inited = 0;
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if (spi_inited)
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return;
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/* Initalize ports for communication with SPI units. */
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U0CTL = CHAR + SYNC + MM + SWRST; /* SW reset,8-bit transfer, SPI master */
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U0TCTL = CKPH + SSEL1 + STC; /* Data on Rising Edge, SMCLK, 3-wire. */
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U0BR0 = 0x02; /* SPICLK set baud. */
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U0BR1 = 0; /* Dont need baud rate control register 2 - clear it */
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U0MCTL = 0; /* Dont need modulation control. */
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P3SEL |= BV(SCK) | BV(MOSI) | BV(MISO); /* Select Peripheral functionality */
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P3DIR |= BV(SCK) | BV(MISO); /* Configure as outputs(SIMO,CLK). */
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ME1 |= USPIE0; /* Module enable ME1 --> U0ME? xxx/bg */
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U0CTL &= ~SWRST; /* Remove RESET */
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}
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