+++ /dev/null
-/*
- * Copyright (c) 2009 Communication Group and Eislab at
- * Lulea University of Technology
- *
- * Contact: Laurynas Riliskis, LTU
- * Mail: laurynas.riliskis@ltu.se
- * All rights reserved.
- *
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- * - Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- * - 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.
- * - Neither the name of Communication Group at Lulea University of Technology
- * 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 COPYRIGHT HOLDERS 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 STANFORD
- * UNIVERSITY OR ITS 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.
- */
-
-/**
- * Mulle specific implementation of a software I2C bus.
- *
- * @author Gong Liang
- * @author Henrik Makitaavola <henrik.makitaavola@gmail.com>
- */
-generic module SoftI2CBusP()
-{
- provides interface SoftI2CBus as I2C;
-
- uses interface GeneralIO as I2CClk;
- uses interface GeneralIO as I2CData;
- uses interface GeneralIO as I2CCtrl;
-}
-implementation
-{
- /***************************************************************************************/
- // Name:idle(), transition(),halfTransition()
- // I2C-bus can be transferred at rates of up to 100 kbit/s in the Standard-mode
- // 10MHz main clock frequency
- // The Baud rate of IIC bus communication can be adjusted by altering the loop times.
- /***************************************************************************************/
- // TODO(henrik) This must be altered to support different main clock speeds.
- void idle(void)
- {
- volatile long int i;
- for(i=0;i<1000;i++)
- {
- asm("nop");
- }
- }
-
- void transition(void)
- {
- volatile int i;
- for(i=0;i<100;i++)
- {
- asm("nop");
- }
- }
-
- void halfTransition(void)
- {
- volatile int i;
- for(i=0;i<50;i++)
- {
- asm("nop");
- }
- }
-
-
- async command void I2C.init()
- {
- call I2CData.makeOutput();
- call I2CClk.makeOutput();
- call I2CCtrl.makeOutput();
- call I2CCtrl.set();
- call I2CData.set(); // drive bus high (default)
- call I2CClk.set(); // drive bus high (default)
- }
-
- async command void I2C.off()
- {
- // TODO(henrik): Exactly what should be set if I2C bus should be turned off?
- call I2CData.makeOutput();
- call I2CClk.makeOutput();
- call I2CCtrl.makeOutput();
- call I2CCtrl.clr();
- call I2CClk.clr();
- call I2CData.clr();
- }
-
- async command void I2C.start()
- {
- atomic
- {
- call I2CData.makeOutput();
- call I2CClk.clr();
- call I2CData.set();
- idle();
- call I2CClk.set();
- idle();
- call I2CData.clr();
- idle();
- call I2CClk.clr();
- idle();
- }
- }
-
- async command void I2C.stop()
- {
- atomic
- {
- call I2CData.makeOutput();
-
- call I2CData.set();
- call I2CClk.clr();
- idle();
- call I2CData.clr();
- idle();
- call I2CClk.set();
- idle();
- call I2CData.set();
- idle();
- }
- }
-
- async command void I2C.restart()
- {
- atomic
- {
- call I2CClk.clr();
- call I2CData.set();
- call I2CClk.set();
- idle();
- call I2CData.clr();
- idle();
- call I2CClk.clr();
- }
- }
-
- async command uint8_t I2C.readByte(bool ack)
- {
- uint8_t retChar;
- uint8_t bitCnt;
-
- atomic
- {
- call I2CData.makeInput();
-
- retChar = 0;
-
- for (bitCnt=0; bitCnt<8; ++bitCnt)
- {
- asm("nop");
- call I2CClk.clr();
- transition();
-
- call I2CClk.set(); // Validate the RevData on the SDA2 line
- halfTransition();
- retChar<<=1; // Push each received bit toward MSB
- if(call I2CData.get() == 1) retChar+=1; // Read the bit on SDA2 line
- halfTransition();
- }
-
- call I2CClk.clr();
- if (ack)
- {
- call I2C.masterAck();
- }
- else
- {
- call I2C.masterNack();
- }
- }
- return retChar;
- }
-
- async command void I2C.writeByte(uint8_t byte)
- {
- uint8_t bitCnt;
-
- atomic
- {
- call I2CData.makeOutput();
-
- for (bitCnt=0; bitCnt<8; ++bitCnt)
- {
- if ((byte<<bitCnt) & 0x80)
- {
- call I2CData.set(); // MSB sending logic
- }
- else
- {
- call I2CData.clr();
- }
- transition(); // Use this function to adjust the baut rate of I2C bus
-
- call I2CClk.set(); //Set SCL2 high to inform slave of receiving sth.
- transition(); // Greater than 4¦Ìs
- call I2CClk.clr();
- }
-
-
- call I2CData.set(); // Release SDA2 for ACK-waiting after sending 8 bits
- transition();
-
- call I2CClk.set();
- transition();
- call I2CClk.clr();
-
- idle();
- }
- }
-
- async command void I2C.masterAck()
- {
- atomic
- {
- call I2CData.makeOutput();
- call I2CClk.clr();
- call I2CData.clr(); // Low for ack
- transition();
- call I2CClk.set();
- transition();
- call I2CClk.clr();
-
- call I2CData.makeInput();
- }
- }
-
- async command void I2C.masterNack()
- {
- atomic
- {
- call I2CData.makeOutput();
- call I2CClk.clr();
-
- call I2CData.set(); // High for nack
- transition();
- call I2CClk.set();
- transition();
- call I2CClk.clr();
-
- call I2CData.makeInput();
- }
- }
-}
projects / tinyos-2.x.git / blobdiff