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CommandStation-EX/I2CManager_Wire.h
2022-07-30 10:40:45 +02:00

127 lines
4.9 KiB
C

/*
* © 2021, Neil McKechnie. All rights reserved.
*
* This file is part of CommandStation-EX
*
* This 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 3 of the License, or
* (at your option) any later version.
*
* It 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 CommandStation. If not, see <https://www.gnu.org/licenses/>.
*/
#ifndef I2CMANAGER_WIRE_H
#define I2CMANAGER_WIRE_H
#include <Arduino.h>
#include <Wire.h>
#include "I2CManager.h"
// This module is only compiled if I2C_USE_WIRE is defined, so define it here
// to get intellisense to work correctly.
#if !defined(I2C_USE_WIRE)
#define I2C_USE_WIRE
#endif
/***************************************************************************
* Initialise I2C interface software
***************************************************************************/
void I2CManagerClass::_initialise() {
Wire.begin();
}
/***************************************************************************
* Set I2C clock speed. Normally 100000 (Standard) or 400000 (Fast)
* on Arduino. Mega4809 supports 1000000 (Fast+) too.
***************************************************************************/
void I2CManagerClass::_setClock(unsigned long i2cClockSpeed) {
Wire.setClock(i2cClockSpeed);
}
/***************************************************************************
* Initiate a write to an I2C device (blocking operation on Wire)
***************************************************************************/
uint8_t I2CManagerClass::write(uint8_t address, const uint8_t buffer[], uint8_t size, I2CRB *rb) {
Wire.beginTransmission(address);
if (size > 0) Wire.write(buffer, size);
rb->status = Wire.endTransmission();
return I2C_STATUS_OK;
}
/***************************************************************************
* Initiate a write from PROGMEM (flash) to an I2C device (blocking operation on Wire)
***************************************************************************/
uint8_t I2CManagerClass::write_P(uint8_t address, const uint8_t buffer[], uint8_t size, I2CRB *rb) {
uint8_t ramBuffer[size];
const uint8_t *p1 = buffer;
for (uint8_t i=0; i<size; i++)
ramBuffer[i] = GETFLASH(p1++);
return write(address, ramBuffer, size, rb);
}
/***************************************************************************
* Initiate a write (optional) followed by a read from the I2C device (blocking operation on Wire)
* If fewer than the number of requested bytes are received, status is I2C_STATUS_TRUNCATED.
***************************************************************************/
uint8_t I2CManagerClass::read(uint8_t address, uint8_t readBuffer[], uint8_t readSize,
const uint8_t writeBuffer[], uint8_t writeSize, I2CRB *rb)
{
uint8_t status = I2C_STATUS_OK;
uint8_t nBytes = 0;
if (writeSize > 0) {
Wire.beginTransmission(address);
Wire.write(writeBuffer, writeSize);
status = Wire.endTransmission(false); // Don't free bus yet
}
if (status == I2C_STATUS_OK) {
Wire.requestFrom(address, (size_t)readSize);
while (Wire.available() && nBytes < readSize)
readBuffer[nBytes++] = Wire.read();
if (nBytes < readSize) status = I2C_STATUS_TRUNCATED;
}
rb->nBytes = nBytes;
rb->status = status;
return I2C_STATUS_OK;
}
/***************************************************************************
* Function to queue a request block and initiate operations.
*
* For the Wire version, this executes synchronously, but the status is
* returned in the I2CRB as for the asynchronous version.
***************************************************************************/
void I2CManagerClass::queueRequest(I2CRB *req) {
switch (req->operation) {
case OPERATION_READ:
req->status = read(req->i2cAddress, req->readBuffer, req->readLen, NULL, 0, req);
break;
case OPERATION_SEND:
req->status = write(req->i2cAddress, req->writeBuffer, req->writeLen, req);
break;
case OPERATION_SEND_P:
req->status = write_P(req->i2cAddress, req->writeBuffer, req->writeLen, req);
break;
case OPERATION_REQUEST:
req->status = read(req->i2cAddress, req->readBuffer, req->readLen, req->writeBuffer, req->writeLen, req);
break;
}
}
/***************************************************************************
* Loop function, for general background work
***************************************************************************/
void I2CManagerClass::loop() {}
// Loop function
void I2CManagerClass::checkForTimeout() {}
#endif