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CommandStation-EX/IO_PCA9554.h
2024-09-30 13:58:40 +08:00

117 lines
3.9 KiB
C++

/*
* © 2024, Paul M. Antoine
* © 2021, Neil McKechnie. All rights reserved.
*
* This file is part of DCC++EX API
*
* 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 io_pca9554_h
#define io_pca9554_h
#include "IO_GPIOBase.h"
#include "FSH.h"
/////////////////////////////////////////////////////////////////////////////////////////////////////
/*
* IODevice subclass for PCA9554 and TCA9554/9534 8-bit I/O expanders (NXP & Texas Instruments).
*/
class PCA9554 : public GPIOBase<uint8_t> {
public:
static void create(VPIN vpin, uint8_t nPins, I2CAddress i2cAddress, int interruptPin=-1) {
if (checkNoOverlap(vpin, nPins, i2cAddress)) new PCA9554(vpin,nPins, i2cAddress, interruptPin);
}
private:
// Constructor
PCA9554(VPIN vpin, uint8_t nPins, I2CAddress I2CAddress, int interruptPin=-1)
: GPIOBase<uint8_t>((FSH *)F("PCA9554"), vpin, nPins, I2CAddress, interruptPin)
{
if (nPins > 8) {
DIAG(F("PCA9554 nPins %d larger than allowed!"));
nPins = 8;
}
requestBlock.setRequestParams(_I2CAddress, inputBuffer, sizeof(inputBuffer),
outputBuffer, sizeof(outputBuffer));
outputBuffer[0] = REG_INPUT_P0;
}
void _writeGpioPort() override {
I2CManager.write(_I2CAddress, 2, REG_OUTPUT_P0, _portOutputState);
}
void _writePullups() override {
// Do nothing, pull-ups are always in place for input ports
// This function is here for HAL GPIOBase API compatibilitiy
}
void _writePortModes() override {
// Write 0 to REG_CONF_P0 for in-use pins that are outputs, 1 for inputs.
// PCA9554 & TCA9555, Interrupt is always enabled for raising and falling edge
uint8_t temp = ~(_portMode & _portInUse);
I2CManager.write(_I2CAddress, 2, REG_CONF_P0, temp);
}
void _readGpioPort(bool immediate) override {
if (immediate) {
uint8_t buffer[2];
I2CManager.read(_I2CAddress, buffer, 1, 1, REG_INPUT_P0);
_portInputState = buffer[0] | _portMode;
/* PCA9554 Int bug fix, from PCA9554 datasheet: "must change command byte to something besides 00h
* after a Read operation to the PCA9554 device or before reading from
* another device"
* Recommended solution, read from REG_OUTPUT_P0, then do nothing with the received data
* Issue not seen during testing, uncomment if needed
*/
//I2CManager.read(_I2CAddress, buffer, 1, 1, REG_OUTPUT_P0);
} else {
// Queue new request
requestBlock.wait(); // Wait for preceding operation to complete
// Issue new request to read GPIO register
I2CManager.queueRequest(&requestBlock);
}
}
// This function is invoked when an I/O operation on the requestBlock completes.
void _processCompletion(uint8_t status) override {
if (status == I2C_STATUS_OK)
{
if (_portInputState != (inputBuffer[0] | _portMode))
DIAG(F("PCA9554 inputs changed, value now %x"), inputBuffer[0]);
_portInputState = inputBuffer[0] | _portMode;
}
else
_portInputState = 0xff;
}
void _setupDevice() override {
// HAL API calls
_writePortModes();
_writePullups();
_writeGpioPort();
}
uint8_t inputBuffer[2];
uint8_t outputBuffer[1];
enum {
REG_INPUT_P0 = 0x00,
REG_OUTPUT_P0 = 0x01,
REG_POL_INV_P0 = 0x02,
REG_CONF_P0 = 0x03,
};
};
#endif