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GPIO PCA9555 / TCA9555 support

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My 1st commit, be gentle
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kempe63 2023-07-29 20:34:39 +01:00
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IO_PCA9555.h Normal file
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/*
* © 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_pca9555_h
#define io_pca9555_h
#include "IO_GPIOBase.h"
#include "FSH.h"
/////////////////////////////////////////////////////////////////////////////////////////////////////
/*
* IODevice subclass for PCA9555 16-bit I/O expander (NXP & Texas Instruments).
*/
class PCA9555 : public GPIOBase<uint16_t> {
public:
static void create(VPIN vpin, int nPins, uint8_t I2CAddress, int interruptPin=-1) {
new PCA9555(vpin, min(nPins,16), I2CAddress, interruptPin);
}
// Constructor
PCA9555(VPIN vpin, int nPins, uint8_t I2CAddress, int interruptPin=-1)
: GPIOBase<uint16_t>((FSH *)F("PCA9555"), vpin, nPins, I2CAddress, interruptPin)
{
requestBlock.setRequestParams(_I2CAddress, inputBuffer, sizeof(inputBuffer),
outputBuffer, sizeof(outputBuffer));
outputBuffer[0] = REG_INPUT_P0;
}
private:
void _writeGpioPort() override {
I2CManager.write(_I2CAddress, 3, REG_OUTPUT_P0, _portOutputState, _portOutputState>>8);
}
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 & REG_CONF_P1 for in-use pins that are outputs, 1 for others.
// PCA9555 & TCA9555, Interrupt is always enabled for raising and falling edge
uint16_t temp = ~(_portMode & _portInUse);
I2CManager.write(_I2CAddress, 3, REG_CONF_P0, temp, temp>>8);
}
void _readGpioPort(bool immediate) override {
if (immediate) {
uint8_t buffer[2];
I2CManager.read(_I2CAddress, buffer, 2, 1, REG_INPUT_P0);
_portInputState = ((uint16_t)buffer[1]<<8) | buffer[0];
/* PCA9555 Int bug fix, from PCA9555 datasheet: "must change command byte to something besides 00h
* after a Read operation to the PCA9555 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, 2, 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)
_portInputState = ((uint16_t)inputBuffer[1]<<8) | inputBuffer[0];
else
_portInputState = 0xffff;
}
void _setupDevice() override {
// HAL API calls
_writePortModes();
_writePullups();
_writeGpioPort();
}
uint8_t inputBuffer[2];
uint8_t outputBuffer[1];
enum {
REG_INPUT_P0 = 0x00,
REG_INPUT_P1 = 0x01,
REG_OUTPUT_P0 = 0x02,
REG_OUTPUT_P1 = 0x03,
REG_POL_INV_P0 = 0x04,
REG_POL_INV_P1 = 0x05,
REG_CONF_P0 = 0x06,
REG_CONF_P1 = 0x07,
};
};
#endif