mirror of
https://github.com/DCC-EX/CommandStation-EX.git
synced 2024-11-24 00:26:13 +01:00
766fdc43ac
Corrections to I2C code: 1) I2CManager_Mega4809.h: Correct bitwise 'and' to logical 'and' - no impact. 2) I2CManager_Wire.h: Ensure that error codes from Wire subsystem are passed back to caller in queueRequest().
128 lines
4.9 KiB
C
128 lines
4.9 KiB
C
/*
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* © 2021, Neil McKechnie. All rights reserved.
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*
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* This file is part of CommandStation-EX
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*
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* This is free software: you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation, either version 3 of the License, or
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* (at your option) any later version.
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*
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* It is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with CommandStation. If not, see <https://www.gnu.org/licenses/>.
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*/
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#ifndef I2CMANAGER_WIRE_H
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#define I2CMANAGER_WIRE_H
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#include <Arduino.h>
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#include <Wire.h>
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#include "I2CManager.h"
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// This module is only compiled if I2C_USE_WIRE is defined, so define it here
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// to get intellisense to work correctly.
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#if !defined(I2C_USE_WIRE)
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#define I2C_USE_WIRE
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#endif
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/***************************************************************************
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* Initialise I2C interface software
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***************************************************************************/
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void I2CManagerClass::_initialise() {
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Wire.begin();
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}
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/***************************************************************************
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* Set I2C clock speed. Normally 100000 (Standard) or 400000 (Fast)
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* on Arduino. Mega4809 supports 1000000 (Fast+) too.
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***************************************************************************/
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void I2CManagerClass::_setClock(unsigned long i2cClockSpeed) {
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Wire.setClock(i2cClockSpeed);
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}
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/***************************************************************************
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* Initiate a write to an I2C device (blocking operation on Wire)
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***************************************************************************/
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uint8_t I2CManagerClass::write(uint8_t address, const uint8_t buffer[], uint8_t size, I2CRB *rb) {
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Wire.beginTransmission(address);
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if (size > 0) Wire.write(buffer, size);
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rb->status = Wire.endTransmission();
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return I2C_STATUS_OK;
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}
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/***************************************************************************
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* Initiate a write from PROGMEM (flash) to an I2C device (blocking operation on Wire)
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***************************************************************************/
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uint8_t I2CManagerClass::write_P(uint8_t address, const uint8_t buffer[], uint8_t size, I2CRB *rb) {
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uint8_t ramBuffer[size];
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const uint8_t *p1 = buffer;
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for (uint8_t i=0; i<size; i++)
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ramBuffer[i] = GETFLASH(p1++);
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return write(address, ramBuffer, size, rb);
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}
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/***************************************************************************
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* Initiate a write (optional) followed by a read from the I2C device (blocking operation on Wire)
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* If fewer than the number of requested bytes are received, status is I2C_STATUS_TRUNCATED.
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***************************************************************************/
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uint8_t I2CManagerClass::read(uint8_t address, uint8_t readBuffer[], uint8_t readSize,
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const uint8_t writeBuffer[], uint8_t writeSize, I2CRB *rb)
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{
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uint8_t status = I2C_STATUS_OK;
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uint8_t nBytes = 0;
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if (writeSize > 0) {
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Wire.beginTransmission(address);
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Wire.write(writeBuffer, writeSize);
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status = Wire.endTransmission(false); // Don't free bus yet
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}
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if (status == I2C_STATUS_OK) {
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Wire.requestFrom(address, (size_t)readSize);
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while (Wire.available() && nBytes < readSize)
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readBuffer[nBytes++] = Wire.read();
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if (nBytes < readSize) status = I2C_STATUS_TRUNCATED;
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}
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rb->nBytes = nBytes;
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rb->status = status;
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return I2C_STATUS_OK;
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}
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/***************************************************************************
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* Function to queue a request block and initiate operations.
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*
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* For the Wire version, this executes synchronously.
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* The read/write/write_P functions return I2C_STATUS_OK always, and the
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* completion status of the operation is in the request block, as for
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* the non-blocking version.
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***************************************************************************/
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void I2CManagerClass::queueRequest(I2CRB *req) {
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switch (req->operation) {
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case OPERATION_READ:
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read(req->i2cAddress, req->readBuffer, req->readLen, NULL, 0, req);
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break;
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case OPERATION_SEND:
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write(req->i2cAddress, req->writeBuffer, req->writeLen, req);
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break;
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case OPERATION_SEND_P:
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write_P(req->i2cAddress, req->writeBuffer, req->writeLen, req);
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break;
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case OPERATION_REQUEST:
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read(req->i2cAddress, req->readBuffer, req->readLen, req->writeBuffer, req->writeLen, req);
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break;
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}
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}
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/***************************************************************************
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* Loop function, for general background work
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***************************************************************************/
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void I2CManagerClass::loop() {}
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// Loop function
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void I2CManagerClass::checkForTimeout() {}
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#endif |