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CommandStation-EX/IO_I2CRailcom.h
Asbelos dd42390ae9 Prep last packet id
2024-10-21 19:37:39 +01:00

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/*
* © 2024, Henk Kruisbrink & Chris Harlow. All rights reserved.
* © 2023, 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/>.
*/
/*
*
* Dec 2023, Added NXP SC16IS752 I2C Dual UART
* The SC16IS752 has 64 bytes TX & RX FIFO buffer
* First version without interrupts from I2C UART and only RX/TX are used, interrupts may not be
* needed as the RX Fifo holds the reply
*
* Jan 2024, Issue with using both UARTs simultaniously, the secod uart seems to work but the first transmit
* corrupt data. This need more analysis and experimenatation.
* Will push this driver to the dev branch with the uart fixed to 0
* Both SC16IS750 (single uart) and SC16IS752 (dual uart, but only uart 0 is enable)
*
* myHall.cpp configuration syntax:
*
* I2CRailcom::create(1st vPin, vPins, I2C address);
*
* myAutomation configuration
* HAL(I2CRailcom, 1st vPin, vPins, I2C address)
* Parameters:
* 1st vPin : First virtual pin that EX-Rail can control to play a sound, use PLAYSOUND command (alias of ANOUT)
* vPins : Total number of virtual pins allocated (2 vPins are supported, one for each UART)
* 1st vPin for UART 0, 2nd for UART 1
* I2C Address : I2C address of the serial controller, in 0x format
*/
#ifndef IO_I2CRailcom_h
#define IO_I2CRailcom_h
#include "IODevice.h"
#include "I2CManager.h"
#include "DIAG.h"
#include "DCCWaveform.h"
#include "Railcom.h"
// Debug and diagnostic defines, enable too many will result in slowing the driver
#define DIAG_I2CRailcom
class I2CRailcom : public IODevice {
private:
// SC16IS752 defines
uint8_t _UART_CH=0x00; // channel 0 or 1 flips each loop if npins>1
byte _inbuf[12];
byte _outbuf[2];
byte cutoutCounter[2];
Railcom * _channelMonitors[2];
public:
// Constructor
I2CRailcom(VPIN firstVpin, int nPins, I2CAddress i2cAddress){
_firstVpin = firstVpin;
_nPins = nPins;
_I2CAddress = i2cAddress;
_channelMonitors[0]=new Railcom(firstVpin);
if (nPins>1) _channelMonitors[1]=new Railcom(firstVpin+1);
addDevice(this);
}
public:
static void create(VPIN firstVpin, int nPins, I2CAddress i2cAddress) {
if (nPins>2) nPins=2;
if (checkNoOverlap(firstVpin, nPins, i2cAddress))
new I2CRailcom(firstVpin, nPins, i2cAddress);
}
void _begin() override {
I2CManager.setClock(1000000); // TODO do we need this?
I2CManager.begin();
auto exists=I2CManager.exists(_I2CAddress);
DIAG(F("I2CRailcom: %s UART%S detected"),
_I2CAddress.toString(), exists?F(""):F(" NOT"));
if (!exists) return;
_UART_CH=0;
Init_SC16IS752(); // Initialize UART0
if (_nPins>1) {
_UART_CH=1;
Init_SC16IS752(); // Initialize UART1
}
if (_deviceState==DEVSTATE_INITIALISING) _deviceState=DEVSTATE_NORMAL;
_display();
}
void _loop(unsigned long currentMicros) override {
// Read responses from device
if (_deviceState!=DEVSTATE_NORMAL) return;
// return if in cutout or cutout very soon.
if (!DCCWaveform::isRailcomSampleWindow()) return;
// IF we have 2 channels, flip channels each loop
if (_nPins>1) _UART_CH=_UART_CH?0:1;
// have we read this cutout already?
auto cut=DCCWaveform::getRailcomCutoutCounter();
if (cutoutCounter[_UART_CH]==cut) return;
cutoutCounter[_UART_CH]=cut;
// Read incoming raw Railcom data, and process accordingly
auto inlength = UART_ReadRegister(REG_RXLV);
if (inlength> sizeof(_inbuf)) inlength=sizeof(_inbuf);
_inbuf[0]=0;
if (inlength>0) {
// Read data buffer from UART
_outbuf[0]=(byte)(REG_RHR << 3 | _UART_CH << 1);
I2CManager.read(_I2CAddress, _inbuf, inlength, _outbuf, 1);
}
// HK: Reset FIFO at end of read cycle
UART_WriteRegister(REG_FCR, 0x07,false);
// Ask Railcom to interpret the raw data
_channelMonitors[_UART_CH]->process(_inbuf,inlength);
}
void _display() override {
DIAG(F("I2CRailcom: Configured on Vpins:%u-%u %S"), _firstVpin, _firstVpin+_nPins-1,
(_deviceState!=DEVSTATE_NORMAL) ? F("OFFLINE") : F(""));
}
private:
// SC16IS752 functions
// Initialise SC16IS752 only for this channel
// First a software reset
// Enable FIFO and clear TX & RX FIFO
// Need to set the following registers
// IOCONTROL set bit 1 and 2 to 0 indicating that they are GPIO
// IODIR set all bit to 1 indicating al are output
// IOSTATE set only bit 0 to 1 for UART 0, or only bit 1 for UART 1 //
// LCR bit 7=0 divisor latch (clock division registers DLH & DLL, they store 16 bit divisor),
// WORD_LEN, STOP_BIT, PARITY_ENA and PARITY_TYPE
// MCR bit 7=0 clock divisor devide-by-1 clock input
// DLH most significant part of divisor
// DLL least significant part of divisor
//
// BAUD_RATE, WORD_LEN, STOP_BIT, PARITY_ENA and PARITY_TYPE have been defined and initialized
//
// Communication parameters 8 bit, No parity, 1 stopbit
static const uint8_t WORD_LEN = 0x03; // Value LCR bit 0,1
static const uint8_t STOP_BIT = 0x00; // Value LCR bit 2
static const uint8_t PARITY_ENA = 0x00; // Value LCR bit 3
static const uint8_t PARITY_TYPE = 0x00; // Value LCR bit 4
static const uint32_t BAUD_RATE = 250000;
static const uint8_t PRESCALER = 0x01; // Value MCR bit 7
static const unsigned long SC16IS752_XTAL_FREQ_RAILCOM = 16000000; // Baud rate for Railcom signal
static const uint16_t _divisor = (SC16IS752_XTAL_FREQ_RAILCOM / PRESCALER) / (BAUD_RATE * 16);
void Init_SC16IS752(){
if (_UART_CH==0) { // HK: Currently fixed on ch 0
// only reset on channel 0}
UART_WriteRegister(REG_IOCONTROL, 0x08,false); // UART Software reset
//_deviceState=DEVSTATE_INITIALISING; // ignores error during reset which seems normal. // HK: this line is moved to below
auto iocontrol_readback = UART_ReadRegister(REG_IOCONTROL);
if (iocontrol_readback == 0x00){
_deviceState=DEVSTATE_INITIALISING;
DIAG(F("I2CRailcom: %s SRESET readback: 0x%x"),_I2CAddress.toString(), iocontrol_readback);
} else {
DIAG(F("I2CRailcom: %s SRESET: 0x%x"),_I2CAddress.toString(), iocontrol_readback);
}
}
// HK:
// You write 0x08 to the IOCONTROL register, setting bit 3 (SRESET), as per datasheet 8.18:
// "Software Reset. A write to this bit will reset the device. Once the
// device is reset this bit is automatically set to logic 0"
// So you can not readback the val you have written as this has changed.
// I've added an extra UART_ReadRegister(REG_IOCONTROL) and check if the return value is 0x00
// then set _deviceState=DEVSTATE_INITIALISING;
// HK: only do clear FIFO at end of Init_SC16IS752
//UART_WriteRegister(REG_FCR, 0x07,false); // Reset FIFO, clear RX & TX FIFO (write only)
UART_WriteRegister(REG_MCR, 0x00); // Set MCR to all 0, includes Clock divisor
//UART_WriteRegister(REG_LCR, 0x80); // Divisor latch enabled
UART_WriteRegister(REG_LCR, 0x80 | WORD_LEN | STOP_BIT | PARITY_ENA | PARITY_TYPE); // Divisor latch enabled and comm parameters set
UART_WriteRegister(REG_DLL, (uint8_t)_divisor); // Write DLL
UART_WriteRegister(REG_DLH, (uint8_t)(_divisor >> 8)); // Write DLH
auto lcr_readback = UART_ReadRegister(REG_LCR);
lcr_readback = lcr_readback & 0x7F;
UART_WriteRegister(REG_LCR, lcr_readback); // Divisor latch disabled
//UART_WriteRegister(REG_LCR, WORD_LEN | STOP_BIT | PARITY_ENA | PARITY_TYPE); // Divisor latch disabled
UART_WriteRegister(REG_FCR, 0x07,false); // Reset FIFO, clear RX & TX FIFO (write only)
#ifdef DIAG_I2CRailcom
// HK: Test to see if internal loopback works and if REG_RXLV increment to at least 0x01
// Set REG_MCR bit 4 to 1, Enable Loopback
UART_WriteRegister(REG_MCR, 0x10);
UART_WriteRegister(REG_THR, 0x88, false); // Send 0x88
auto inlen = UART_ReadRegister(REG_RXLV);
if (inlen == 0){
DIAG(F("I2CRailcom: Loopback test: %s/%d failed"),_I2CAddress.toString(), _UART_CH);
} else {
DIAG(F("Railcom: Loopback test: %s/%d RX Fifo lvl: 0x%x"),_I2CAddress.toString(), _UART_CH, inlen);
_outbuf[0]=(byte)(REG_RHR << 3 | _UART_CH << 1);
I2CManager.read(_I2CAddress, _inbuf, inlen, _outbuf, 1);
#ifdef DIAG_I2CRailcom_data
DIAG(F("Railcom: Loopback test: %s/%d RX FIFO Data"), _I2CAddress.toString(), _UART_CH);
for (int i = 0; i < inlen; i++){
DIAG(F("Railcom: Loopback data [0x%x]: 0x%x"), i, _inbuf[i]);
//DIAG(F("[0x%x]: 0x%x"), i, _inbuf[i]);
}
#endif
}
UART_WriteRegister(REG_MCR, 0x00); // Set REG_MCR back to 0x00
#endif
#ifdef DIAG_I2CRailcom
// Sent some data to check if UART baudrate is set correctly, check with logic analyzer on TX pin
UART_WriteRegister(REG_THR, 9, false);
DIAG(F("I2CRailcom: UART %s/%d Test TX = 0x09"),_I2CAddress.toString(), _UART_CH);
#endif
if (_deviceState==DEVSTATE_INITIALISING) {
DIAG(F("I2CRailcom: UART %d init complete"),_UART_CH);
}
// HK: final FIFO reset
UART_WriteRegister(REG_FCR, 0x07,false); // Reset FIFO, clear RX & TX FIFO (write only)
}
void UART_WriteRegister(uint8_t reg, uint8_t val, bool readback=true){
_outbuf[0] = (byte)( reg << 3 | _UART_CH << 1);
_outbuf[1]=val;
auto status=I2CManager.write(_I2CAddress, _outbuf, (uint8_t)2);
if(status!=I2C_STATUS_OK) {
DIAG(F("I2CRailcom: %s/%d write reg=0x%x,data=0x%x,I2Cstate=%d"),
_I2CAddress.toString(), _UART_CH, reg, val, status);
_deviceState=DEVSTATE_FAILED;
}
if (readback) { // Read it back to cross check
auto readback=UART_ReadRegister(reg);
if (readback!=val) {
DIAG(F("I2CRailcom readback: %s/%d reg:0x%x write=0x%x read=0x%x"),_I2CAddress.toString(),_UART_CH,reg,val,readback);
}
}
}
uint8_t UART_ReadRegister(uint8_t reg){
_outbuf[0] = (byte)(reg << 3 | _UART_CH << 1); // _outbuffer[0] has now UART_REG and UART_CH
_inbuf[0]=0;
auto status=I2CManager.read(_I2CAddress, _inbuf, 1, _outbuf, 1);
if (status!=I2C_STATUS_OK) {
DIAG(F("I2CRailcom read: %s/%d read reg=0x%x,I2Cstate=%d"),
_I2CAddress.toString(), _UART_CH, reg, status);
_deviceState=DEVSTATE_FAILED;
}
return _inbuf[0];
}
// SC16IS752 General register set (from the datasheet)
enum : uint8_t {
REG_RHR = 0x00, // FIFO Read
REG_THR = 0x00, // FIFO Write
REG_IER = 0x01, // Interrupt Enable Register R/W
REG_FCR = 0x02, // FIFO Control Register Write
REG_IIR = 0x02, // Interrupt Identification Register Read
REG_LCR = 0x03, // Line Control Register R/W
REG_MCR = 0x04, // Modem Control Register R/W
REG_LSR = 0x05, // Line Status Register Read
REG_MSR = 0x06, // Modem Status Register Read
REG_SPR = 0x07, // Scratchpad Register R/W
REG_TCR = 0x06, // Transmission Control Register R/W
REG_TLR = 0x07, // Trigger Level Register R/W
REG_TXLV = 0x08, // Transmitter FIFO Level register Read
REG_RXLV = 0x09, // Receiver FIFO Level register Read
REG_IODIR = 0x0A, // Programmable I/O pins Direction register R/W
REG_IOSTATE = 0x0B, // Programmable I/O pins State register R/W
REG_IOINTENA = 0x0C, // I/O Interrupt Enable register R/W
REG_IOCONTROL = 0x0E, // I/O Control register R/W
REG_EFCR = 0x0F, // Extra Features Control Register R/W
};
// SC16IS752 Special register set
enum : uint8_t{
REG_DLL = 0x00, // Division registers R/W
REG_DLH = 0x01, // Division registers R/W
};
// SC16IS752 Enhanced regiter set
enum : uint8_t{
REG_EFR = 0X02, // Enhanced Features Register R/W
REG_XON1 = 0x04, // R/W
REG_XON2 = 0x05, // R/W
REG_XOFF1 = 0x06, // R/W
REG_XOFF2 = 0x07, // R/W
};
};
#endif // IO_I2CRailcom_h
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