forked from collin80/FlexCAN_Library
/
FlexCAN.cpp
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FlexCAN.cpp
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// -------------------------------------------------------------
// a simple Arduino Teensy 3.1/3.2/3.5/3.6 CAN driver
// by teachop
// dual CAN support for MK66FX1M0 and updates for MK64FX512 by Pawelsky
// Interrupt driven Rx/Tx with buffers, object oriented callbacks by Collin Kidder
// RTR related code by H4nky84
// Statistics collection, timestamp and code clean-up my mdapoz
//
#include "FlexCAN.h"
#include "kinetis_flexcan.h"
#define FLEXCANb_MCR(b) (*(vuint32_t*)(b))
#define FLEXCANb_CTRL1(b) (*(vuint32_t*)(b+4))
#define FLEXCANb_RXMGMASK(b) (*(vuint32_t*)(b+0x10))
#define FLEXCANb_IFLAG1(b) (*(vuint32_t*)(b+0x30))
#define FLEXCANb_IMASK1(b) (*(vuint32_t*)(b+0x28))
#define FLEXCANb_RXFGMASK(b) (*(vuint32_t*)(b+0x48))
#define FLEXCANb_MBn_CS(b, n) (*(vuint32_t*)(b+0x80+n*0x10))
#define FLEXCANb_MBn_ID(b, n) (*(vuint32_t*)(b+0x84+n*0x10))
#define FLEXCANb_MBn_WORD0(b, n) (*(vuint32_t*)(b+0x88+n*0x10))
#define FLEXCANb_MBn_WORD1(b, n) (*(vuint32_t*)(b+0x8C+n*0x10))
#define FLEXCANb_IDFLT_TAB(b, n) (*(vuint32_t*)(b+0xE0+(n*4)))
#define FLEXCANb_MB_MASK(b, n) (*(vuint32_t*)(b+0x880+(n*4)))
#define FLEXCANb_ESR1(b) (*(vuint32_t*)(b+0x20))
#if defined(__MK66FX1M0__)
# define INCLUDE_FLEXCAN_CAN1
#endif
#undef INCLUDE_FLEXCAN_DEBUG
#if defined(INCLUDE_FLEXCAN_DEBUG)
# define dbg_print(fmt, args...) Serial.print (fmt , ## args)
# define dbg_println(fmt, args...) Serial.println (fmt , ## args)
#else
# define dbg_print(fmt, args...)
# define dbg_println(fmt, args...)
#endif
// Supported FlexCAN interfaces
FlexCAN Can0 (0);
#if defined(INCLUDE_FLEXCAN_CAN1)
FlexCAN Can1 (1);
#endif
// default mask to apply to all mailboxes
CAN_filter_t FlexCAN::defaultMask;
// Some of these are complete guesses. Only really 8 and 16 have been validated.
// You have been warned. But, there aren't too many options for some of these
uint8_t bitTimingTable[21][3] = {
// prop, seg1, seg2 (4 + prop + seg1 + seg2, seg2 must be at least 1)
// No value can go over 7 here.
{0,0,1}, //5
{1,0,1}, //6
{1,1,1}, //7
{2,1,1}, //8
{2,2,1}, //9
{2,3,1}, //10
{2,3,2}, //11
{2,4,2}, //12
{2,5,2}, //13
{2,5,3}, //14
{2,6,3}, //15
{2,7,3}, //16
{2,7,4}, //17
{3,7,4}, //18
{3,7,5}, //19
{4,7,5}, //20
{4,7,6}, //21
{5,7,6}, //22
{6,7,6}, //23
{6,7,7}, //24
{7,7,7}, //25
};
/*
* \brief Initialize the FlexCAN driver class
*
* \param id - CAN bus interface selection
*
* \retval none
*
*/
FlexCAN::FlexCAN (uint8_t id)
{
uint32_t i;
numTxMailboxes=2;
flexcanBase = FLEXCAN0_BASE;
#if defined (INCLUDE_FLEXCAN_CAN1)
if (id > 0) {
flexcanBase = FLEXCAN1_BASE;
}
#else
(void)id; // Just for avoid warning.
#endif
#if defined(__MK20DX256__)
IrqMessage=IRQ_CAN_MESSAGE;
#elif defined(__MK64FX512__)
IrqMessage=IRQ_CAN0_MESSAGE;
#elif defined(__MK66FX1M0__)
if (flexcanBase == FLEXCAN0_BASE) {
IrqMessage=IRQ_CAN0_MESSAGE;
} else {
IrqMessage=IRQ_CAN1_MESSAGE;
}
#endif
// Default mask is allow everything
defaultMask.flags.remote = 0;
defaultMask.flags.extended = 0;
defaultMask.id = 0;
sizeRxBuffer=SIZE_RX_BUFFER;
sizeTxBuffer=SIZE_TX_BUFFER;
tx_buffer=0;
rx_buffer=0;
// Initialize all message box spesific ring buffers to 0.
for (i=0; i<getNumMailBoxes(); i++) {
txRings[i]=0;
}
// clear any listeners for received packets
for (i = 0; i < SIZE_LISTENERS; i++) {
listener[i] = NULL;
}
// clear statistics counts
clearStats ();
}
/*
* \brief Bring the hardware into freeze which drops it off the CAN bus
*
* \param none
*
* \retval none
*
*/
void FlexCAN::end (void)
{
// enter freeze mode
halt();
FLEXCANb_MCR (flexcanBase) |= (FLEXCAN_MCR_HALT);
while (!(FLEXCANb_MCR(flexcanBase) & FLEXCAN_MCR_FRZ_ACK))
;
}
/*
* \brief Initializes the CAN bus to the given settings
*
* \param baud - Set the baud rate of the bus. Only certain values are valid 50000, 100000, 125000, 250000, 500000, 1000000
* \param mask - A default mask to use for all mailbox masks. Optional.
* \param txAlt - 1 to enable alternate Tx pin (where available)
* \param rxAlt - 1 to enable alternate Rx pin (where available)
*
* \retval none
*
*/
void FlexCAN::begin (uint32_t baud, const CAN_filter_t &mask, uint8_t txAlt, uint8_t rxAlt)
{
initializeBuffers();
// set up the pins
setPins(txAlt,rxAlt);
// select clock source 16MHz xtal
OSC0_CR |= OSC_ERCLKEN;
if (flexcanBase == FLEXCAN0_BASE) {
SIM_SCGC6 |= SIM_SCGC6_FLEXCAN0;
#if defined(INCLUDE_FLEXCAN_CAN1)
} else if (flexcanBase == FLEXCAN1_BASE) {
SIM_SCGC3 |= SIM_SCGC3_FLEXCAN1;
#endif
}
FLEXCANb_CTRL1(flexcanBase) &= ~FLEXCAN_CTRL_CLK_SRC;
// enable CAN
FLEXCANb_MCR (flexcanBase) |= FLEXCAN_MCR_FRZ;
FLEXCANb_MCR (flexcanBase) &= ~FLEXCAN_MCR_MDIS;
while (FLEXCANb_MCR(flexcanBase) & FLEXCAN_MCR_LPM_ACK)
;
// soft reset
softReset();
// wait for freeze ack
waitFrozen();
// disable self-reception
FLEXCANb_MCR (flexcanBase) |= FLEXCAN_MCR_SRX_DIS;
setBaudRate(baud);
// enable per-mailbox filtering
FLEXCANb_MCR(flexcanBase) |= FLEXCAN_MCR_IRMQ;
// now have to set mask and filter for all the Rx mailboxes or they won't receive anything by default.
for (uint8_t c = 0; c < getNumRxBoxes(); c++) {
setMask (0, c);
setFilter (mask, c);
}
// start the CAN
exitHalt();
waitReady();
setNumTxBoxes (numTxMailboxes);
NVIC_SET_PRIORITY (IrqMessage, IRQ_PRIORITY);
NVIC_ENABLE_IRQ (IrqMessage);
// enable interrupt masks for all 16 mailboxes
FLEXCANb_IMASK1 (flexcanBase) = 0xFFFF;
dbg_println ("CAN initialized properly");
}
/*
* \brief
*
* \param
*
* \retval None.
*
*/
void FlexCAN::setMailBoxTxBufferSize(uint8_t mbox, uint16_t size) {
if ( mbox>=getNumMailBoxes() || txRings[mbox]!=0 ) return;
volatile CAN_message_t *buf=new CAN_message_t[size];
txRings[mbox]=new ringbuffer_t;
initRingBuffer (*(txRings[mbox]), buf, size);
}
/*
* \brief Initializes dynamically sized buffers.
*
* \param mask - default filter mask
*
* \retval None.
*
*/
void FlexCAN::initializeBuffers() {
if ( isInitialized() ) return;
// set up the transmit and receive ring buffers
if (tx_buffer==0) tx_buffer=new CAN_message_t[sizeTxBuffer];
if (rx_buffer==0) rx_buffer=new CAN_message_t[sizeRxBuffer];
initRingBuffer (txRing, tx_buffer, sizeTxBuffer);
initRingBuffer (rxRing, rx_buffer, sizeRxBuffer);
}
/*
* \brief Initializes CAN pin definitions.
*
* \param txAlt - Atrenate tx pin
* \param rxAlt - Alternate rx pin
*
* \retval None.
*
*/
void FlexCAN::setPins(uint8_t txAlt, uint8_t rxAlt) {
if (flexcanBase == FLEXCAN0_BASE) {
dbg_println ("Begin setup of CAN0");
#if defined(__MK66FX1M0__) || defined(__MK64FX512__)
// 3=PTA12=CAN0_TX, 4=PTA13=CAN0_RX (default)
// 29=PTB18=CAN0_TX, 30=PTB19=CAN0_RX (alternative)
if (txAlt == 1)
CORE_PIN29_CONFIG = PORT_PCR_MUX(2);
else
CORE_PIN3_CONFIG = PORT_PCR_MUX(2);
// | PORT_PCR_PE | PORT_PCR_PS;
if (rxAlt == 1)
CORE_PIN30_CONFIG = PORT_PCR_MUX(2);
else
CORE_PIN4_CONFIG = PORT_PCR_MUX(2);
#else
// 3=PTA12=CAN0_TX, 4=PTA13=CAN0_RX (default)
// 32=PTB18=CAN0_TX, 25=PTB19=CAN0_RX (alternative)
if (txAlt == 1)
CORE_PIN32_CONFIG = PORT_PCR_MUX(2);
else
CORE_PIN3_CONFIG = PORT_PCR_MUX(2);
// | PORT_PCR_PE | PORT_PCR_PS;
if (rxAlt == 1)
CORE_PIN25_CONFIG = PORT_PCR_MUX(2);
else
CORE_PIN4_CONFIG = PORT_PCR_MUX(2);
#endif
}
#if defined(INCLUDE_FLEXCAN_CAN1)
else if (flexcanBase == FLEXCAN1_BASE) {
dbg_println("Begin setup of CAN1");
// 33=PTE24=CAN1_TX, 34=PTE25=CAN1_RX (default)
// NOTE: Alternative CAN1 pins are not broken out on Teensy 3.6
CORE_PIN33_CONFIG = PORT_PCR_MUX(2);
CORE_PIN34_CONFIG = PORT_PCR_MUX(2);// | PORT_PCR_PE | PORT_PCR_PS;
}
#endif
}
/*
* \brief Intializes bus baud rate setting.
*
* \param baud - desired baud rate
*
* \retval None.
*
now using a system that tries to automatically generate a viable baud setting.
Bear these things in mind:
- The master clock is 16Mhz
- You can freely divide it by anything from 1 to 256
- There is always a start bit (+1)
- The rest (prop, seg1, seg2) are specified 1 less than their actual value (aka +1)
- This gives the low end bit timing as 5 (1 + 1 + 2 + 1) and the high end 25 (1 + 8 + 8 + 8)
A worked example: 16Mhz clock, divisor = 19+1, bit values add up to 16 = 16Mhz / 20 / 16 = 50k baud
*/
void FlexCAN::setBaudRate(uint32_t baud) {
// have to find a divisor that ends up as close to the target baud as possible while keeping the end result between 5 and 25
dbg_println ("Set baud rate");
uint32_t divisor = 0;
uint32_t bestDivisor = 0;
uint32_t result = 16000000 / baud / (divisor + 1);
int error = baud - (16000000 / (result * (divisor + 1)));
int bestError = error;
while (result > 5) {
divisor++;
result = 16000000 / baud / (divisor + 1);
if (result <= 25) {
error = baud - (16000000 / (result * (divisor + 1)));
if (error < 0)
error *= -1;
// if this error is better than we've ever seen then use it - it's the best option
if (error < bestError) {
bestError = error;
bestDivisor = divisor;
}
// If this is equal to a previously good option then
// switch to it but only if the bit time result was in the middle of the range
// this biases the output to use the middle of the range all things being equal
// Otherwise it might try to use a higher divisor and smaller values for prop, seg1, seg2
// and that's not necessarily the best idea.
if ((error == bestError) && (result > 11) && (result < 19)) {
bestError = error;
bestDivisor = divisor;
}
}
}
divisor = bestDivisor;
result = 16000000 / baud / (divisor + 1);
if ((result < 5) || (result > 25) || (bestError > 300)) {
Serial.println ("Abort in CAN begin. Couldn't find a suitable baud config!");
return;
}
result -= 5; // the bitTimingTable is offset by 5 since there was no reason to store bit timings for invalid numbers
uint8_t propSeg = bitTimingTable[result][0];
uint8_t pSeg1 = bitTimingTable[result][1];
uint8_t pSeg2 = bitTimingTable[result][2];
// baud rate debug information
dbg_println (" Bit time values:");
dbg_print (" Prop = ");
dbg_println (propSeg + 1);
dbg_print (" Seg1 = ");
dbg_println (pSeg1 + 1);
dbg_print (" Seg2 = ");
dbg_println (pSeg2 + 1);
dbg_print (" Divisor = ");
dbg_println (divisor + 1);
FLEXCANb_CTRL1 (flexcanBase) = (FLEXCAN_CTRL_PROPSEG(propSeg) | FLEXCAN_CTRL_RJW(1) | FLEXCAN_CTRL_ERR_MSK |
FLEXCAN_CTRL_PSEG1(pSeg1) | FLEXCAN_CTRL_PSEG2(pSeg2) | FLEXCAN_CTRL_PRESDIV(divisor));
}
/*
* \brief Halts CAN bus.
*
* \param None.
*
* \retval None.
*
*/
void FlexCAN::halt() {
FLEXCANb_MCR(flexcanBase) |= (FLEXCAN_MCR_HALT);
waitFrozen();
}
/*
* \brief Exits from hat state.
*
* \param None.
*
* \retval None.
*
*/
void FlexCAN::exitHalt() {
// exit freeze mode and wait until it is unfrozen.
dbg_println ("Exit halt");
FLEXCANb_MCR(flexcanBase) &= ~(FLEXCAN_MCR_HALT);
waitNotFrozen();
}
/*
* \brief Makes CAN bus soft reset.
*
* \param None.
*
* \retval None.
*
*/
void FlexCAN::softReset() {
dbg_println ("Soft reset");
FLEXCANb_MCR (flexcanBase) ^= FLEXCAN_MCR_SOFT_RST;
while (FLEXCANb_MCR (flexcanBase) & FLEXCAN_MCR_SOFT_RST)
;
}
/*
* \brief Freezes CAN bus.
*
* \param None.
*
* \retval None.
*
*/
void FlexCAN::freeze() {
FLEXCANb_MCR(flexcanBase) |= FLEXCAN_MCR_FRZ;
}
/*
* \brief Waits until CAN bus is frozen
*
* \param None.
*
* \retval None.
*
*/
void FlexCAN::waitFrozen() {
// wait for freeze ack
dbg_println ("Wait frozen");
while (!isFrozen());
}
/*
* \brief Waits until CAN bus is not frozen.
*
* \param None.
*
* \retval None.
*
*/
void FlexCAN::waitNotFrozen() {
// wait for freeze ack
dbg_println ("Wait not frozen");
while (isFrozen());
}
/*
* \brief Waits until CAN bus is ready
*
* \param None.
*
* \retval None.
*
*/
void FlexCAN::waitReady() {
while (FLEXCANb_MCR(flexcanBase) & FLEXCAN_MCR_NOT_RDY);
}
/*
* \brief Tests is CAN bus frozen.
*
* \param None.
*
* \retval true, if CAN bus is frozen.
*
*/
bool FlexCAN::isFrozen() {
return (FLEXCANb_MCR(flexcanBase) & FLEXCAN_MCR_FRZ_ACK);
}
/*
* \brief Set listen only mode on or off.
*
* \param mode - set listen only mode?
*
* \retval None.
*
*/
void FlexCAN::setListenOnly (bool mode)
{
// enter freeze mode if not already there
if (!(FLEXCANb_MCR(flexcanBase) & FLEXCAN_MCR_FRZ_ACK)) {
FLEXCANb_MCR(flexcanBase) |= FLEXCAN_MCR_FRZ;
FLEXCANb_MCR(flexcanBase) |= FLEXCAN_MCR_HALT;
while (!(FLEXCANb_MCR(flexcanBase) & FLEXCAN_MCR_FRZ_ACK))
;
}
if (mode)
FLEXCANb_CTRL1(flexcanBase) |= FLEXCAN_CTRL_LOM;
else
FLEXCANb_CTRL1(flexcanBase) &= ~FLEXCAN_CTRL_LOM;
// exit freeze mode and wait until it is unfrozen.
FLEXCANb_MCR(flexcanBase) &= ~FLEXCAN_MCR_HALT;
while (FLEXCANb_MCR(flexcanBase) & FLEXCAN_MCR_FRZ_ACK)
;
}
/*
* \brief Initializes mailboxes to the requested mix of Rx and Tx boxes
*
* \param txboxes - How many of the 8 boxes should be used for Tx
*
* \retval number of tx boxes set.
*
*/
uint8_t FlexCAN::setNumTxBoxes (uint8_t txboxes)
{
uint8_t c;
uint32_t oldIde;
if (txboxes > getNumMailBoxes() - 1)
txboxes = getNumMailBoxes() - 1;
if (txboxes < 1)
txboxes = 1;
numTxMailboxes = txboxes;
if ( !isInitialized() ) return numTxMailboxes; // Just set the numTxMailboxes. Begin() will do final initialization.
// Inialize Rx boxen
for (c = 0; c < getNumRxBoxes(); c++) {
// preserve the existing filter ide setting
oldIde = FLEXCANb_MBn_CS(flexcanBase, c) & FLEXCAN_MB_CS_IDE;
FLEXCANb_MBn_CS(flexcanBase, c) = FLEXCAN_MB_CS_CODE(FLEXCAN_MB_CODE_RX_EMPTY) | oldIde;
}
// Initialize Tx boxen
for (c = getFirstTxBox(); c < getNumMailBoxes(); c++) {
FLEXCANb_MBn_CS(flexcanBase, c) = FLEXCAN_MB_CS_CODE(FLEXCAN_MB_CODE_TX_INACTIVE);
}
return (numTxMailboxes);
}
/*
* \brief Sets a per-mailbox filter. Sets both the storage and the actual mailbox.
*
* \param filter - a filled out filter structure
* \param mbox - the mailbox to update
*
* \retval Nothing
*
*/
void FlexCAN::setFilter (const CAN_filter_t &filter, uint8_t mbox)
{
if ( mbox < getNumRxBoxes() ) {
MBFilters[mbox] = filter;
if (filter.flags.extended) {
FLEXCANb_MBn_ID(flexcanBase, mbox) = (filter.id & FLEXCAN_MB_ID_EXT_MASK);
FLEXCANb_MBn_CS(flexcanBase, mbox) |= FLEXCAN_MB_CS_IDE;
} else {
FLEXCANb_MBn_ID(flexcanBase, mbox) = FLEXCAN_MB_ID_IDSTD(filter.id);
FLEXCANb_MBn_CS(flexcanBase, mbox) &= ~FLEXCAN_MB_CS_IDE;
}
}
}
/*
* \brief Gets a per-mailbox filter.
*
* \param filter - returned filter structure
* \param mbox - mailbox selected
*
* \retval true if mailbox s valid, false otherwise
*
*/
bool FlexCAN::getFilter (CAN_filter_t &filter, uint8_t mbox)
{
if ( mbox < getNumRxBoxes() ) {
filter.id = MBFilters[mbox].id;
filter.flags.extended = MBFilters[mbox].flags.extended;
filter.flags.remote = MBFilters[mbox].flags.remote;
filter.flags.reserved = MBFilters[mbox].flags.reserved;
return (true);
}
return (false);
}
/*
* \brief Set the mailbox mask for filtering packets
*
* \param mask - mask to apply.
* \param mbox - mailbox number
*
* \retval None.
*/
void FlexCAN::setMask (uint32_t mask, uint8_t mbox)
{
if ( mbox < getNumRxBoxes() ) {
/* Per mailbox masks can only be set in freeze mode so have to enter that mode if not already there. */
bool wasFrozen=isFrozen();
if (!wasFrozen) {
freeze();
halt();
}
FLEXCANb_MB_MASK(flexcanBase, mbox) = mask;
if (!wasFrozen) exitHalt();
}
}
/*
* \brief How many messages are available to read.
*
* \param None
*
* \retval A count of the number of messages available.
*/
uint32_t FlexCAN::available (void)
{
irqLock();
uint32_t result=(ringBufferCount (rxRing));
irqRelease();
return result;
}
/*
* \brief Clear the collected statistics
*
* \param None
*
* \retval None
*/
#if defined(COLLECT_CAN_STATS)
void FlexCAN::clearStats (void)
{
// initialize the statistics structure
memset (&stats, 0, sizeof(stats));
stats.enabled = false;
stats.ringRxMax = SIZE_RX_BUFFER - 1;
stats.ringTxMax = SIZE_TX_BUFFER - 1;
stats.ringRxFramesLost = 0;
}
#endif
/*
* \brief Retrieve a frame from the RX buffer
*
* \param msg - buffer reference to the frame structure to fill out
*
* \retval 0 no frames waiting to be received, 1 if a frame was returned
*/
int FlexCAN::read (CAN_message_t &msg)
{
/* pull the next available message from the ring */
int result=0;
irqLock();
if (removeFromRingBuffer (rxRing, msg) == true) {
result=1;
}
irqRelease();
return result;
}
/*
* \brief Send a frame out of this canbus port
*
* \param msg - the filled out frame structure to use for sending
*
* \note Will do one of two things - 1. Send the given frame out of the first available mailbox
* or 2. queue the frame for sending later via interrupt. Automatically turns on TX interrupt
* if necessary.
* Messages may be transmitted out of order, if more than one transmit mailbox is enabled.
* The message queue ignores the message priority.
*
* Returns whether sending/queueing succeeded. Will not smash the queue if it gets full.
*/
int FlexCAN::write (const CAN_message_t &msg)
{
uint32_t index=getNumMailBoxes();
int result=0;
irqLock();
if ( isRingBufferEmpty(txRing) ) { // If there is nothing buffered, find free mailbox
for (index = getFirstTxBox(); index < getNumMailBoxes(); index++) {
if ( usesGlobalTxRing(index) && FLEXCAN_get_code(FLEXCANb_MBn_CS(flexcanBase, index)) == FLEXCAN_MB_CODE_TX_INACTIVE ) {
break;// found one
}
}
}
if (index < getNumMailBoxes()) {
dbg_println ("Writing a frame directly.");
writeTxRegisters (msg, index);
result=1;
} else {
// no mailboxes available. Try to buffer it
if (addToRingBuffer (txRing, msg) == true) {
result=1;
}
// else could not send the frame!
}
irqRelease();
return result;
}
/*
* \brief Send a frame out of this canbus port, using a specific mailbox. The TX queue is not used.
*
* \param msg - the filled out frame structure to use for sending
* \param mbox - mailbox selected
*
* \note If the mailbox is available, the message is placed in the mailbox. The CAN controller
* selects the next message to send from all filled transmit mailboxes, based on the priority.
* This method allows callers to not use the transmit queue and prioritize messages by using
* different mailboxes for different priority levels.
* Using the same mailbox for a group of messages enforces the transmit order for this group.
*
* Returns whether the message was placed in the mailbox for sending.
*/
int FlexCAN::write (const CAN_message_t &msg, uint8_t mbox)
{
int result=0;
if ( !isTxBox(mbox) ) return result;
irqLock();
if ( txRings[mbox]==0 || isRingBufferEmpty(*txRings[mbox]) ) {
if ( FLEXCAN_get_code(FLEXCANb_MBn_CS(flexcanBase, mbox)) == FLEXCAN_MB_CODE_TX_INACTIVE ) {
writeTxRegisters (msg, mbox);
result=1;
}
}
if (result==0 && txRings[mbox]!=0 && addToRingBuffer(*txRings[mbox], msg) ) {
result=1;
}
irqRelease();
return result;
}
/*
* \brief Write CAN message to the FlexCAN hardware registers.
*
* \param msg - message structure to send.
* \param buffer - mailbox number to write to.
*
* \retval None.
*
*/
void FlexCAN::writeTxRegisters (const CAN_message_t &msg, uint8_t buffer)
{
// transmit the frame
// Commented below by TTL. That caused lock time to time to FLEXCAN_MB_CODE_TX_ONCE state.
// FLEXCANb_MBn_CS(flexcanBase, buffer) = FLEXCAN_MB_CS_CODE(FLEXCAN_MB_CODE_TX_INACTIVE);
if (msg.flags.extended) {
FLEXCANb_MBn_ID(flexcanBase, buffer) = (msg.id & FLEXCAN_MB_ID_EXT_MASK);
} else {
FLEXCANb_MBn_ID(flexcanBase, buffer) = FLEXCAN_MB_ID_IDSTD(msg.id);
}
FLEXCANb_MBn_WORD0(flexcanBase, buffer) = (msg.buf[0]<<24)|(msg.buf[1]<<16)|(msg.buf[2]<<8)|msg.buf[3];
FLEXCANb_MBn_WORD1(flexcanBase, buffer) = (msg.buf[4]<<24)|(msg.buf[5]<<16)|(msg.buf[6]<<8)|msg.buf[7];
if (msg.flags.extended) {
if (msg.flags.remote) {
FLEXCANb_MBn_CS(flexcanBase, buffer) = FLEXCAN_MB_CS_CODE(FLEXCAN_MB_CODE_TX_ONCE) |
FLEXCAN_MB_CS_LENGTH(msg.len) | FLEXCAN_MB_CS_SRR |
FLEXCAN_MB_CS_IDE | FLEXCAN_MB_CS_RTR;
} else {
FLEXCANb_MBn_CS(flexcanBase, buffer) = FLEXCAN_MB_CS_CODE(FLEXCAN_MB_CODE_TX_ONCE) |
FLEXCAN_MB_CS_LENGTH(msg.len) | FLEXCAN_MB_CS_SRR |
FLEXCAN_MB_CS_IDE;
}
} else {
if (msg.flags.remote) {
FLEXCANb_MBn_CS(flexcanBase, buffer) = FLEXCAN_MB_CS_CODE(FLEXCAN_MB_CODE_TX_ONCE) |
FLEXCAN_MB_CS_LENGTH(msg.len) | FLEXCAN_MB_CS_RTR;
} else {
FLEXCANb_MBn_CS(flexcanBase, buffer) = FLEXCAN_MB_CS_CODE(FLEXCAN_MB_CODE_TX_ONCE) |
FLEXCAN_MB_CS_LENGTH(msg.len);
}
}
}
/*
* \brief Read CAN message from the FlexCAN hardware registers.
*
* \param msg - message structure to fill.
* \param buffer - mailbox number to read from.
*
* \retval None.
*
*/
void FlexCAN::readRxRegisters (CAN_message_t& msg, uint8_t buffer)
{
uint32_t mb_CS = FLEXCANb_MBn_CS(flexcanBase, buffer);
// get identifier and dlc
msg.len = FLEXCAN_get_length (mb_CS);
msg.flags.extended = (mb_CS & FLEXCAN_MB_CS_IDE) ? 1:0;
msg.flags.remote = (mb_CS & FLEXCAN_MB_CS_RTR) ? 1:0;
msg.timestamp = FLEXCAN_get_timestamp (mb_CS);
msg.flags.overrun = 0;
msg.flags.reserved = 0;
msg.id = (FLEXCANb_MBn_ID(flexcanBase, buffer) & FLEXCAN_MB_ID_EXT_MASK);
if (!msg.flags.extended) {
msg.id >>= FLEXCAN_MB_ID_STD_BIT_NO;
}
// check for mailbox buffer overruns
if (FLEXCAN_get_code (mb_CS) == FLEXCAN_MB_CODE_RX_OVERRUN) {
msg.flags.overrun = 1;
}
// copy out message
uint32_t dataIn = FLEXCANb_MBn_WORD0(flexcanBase, buffer);
msg.buf[3] = dataIn;
dataIn >>=8;
msg.buf[2] = dataIn;
dataIn >>=8;
msg.buf[1] = dataIn;
dataIn >>=8;
msg.buf[0] = dataIn;
if (msg.len > 4) {
dataIn = FLEXCANb_MBn_WORD1(flexcanBase, buffer);
msg.buf[7] = dataIn;
dataIn >>=8;
msg.buf[6] = dataIn;
dataIn >>=8;
msg.buf[5] = dataIn;
dataIn >>=8;
msg.buf[4] = dataIn;
}
for (uint32_t loop=msg.len; loop < 8; loop++ ) {
msg.buf[loop] = 0;
}
}
/*
* \brief Initialize the specified ring buffer.
*
* \param ring - ring buffer to initialize.
* \param buffer - buffer to use for storage.
* \param size - size of the buffer in bytes.
*
* \retval None.
*
*/
void FlexCAN::initRingBuffer (ringbuffer_t &ring, volatile CAN_message_t *buffer, uint32_t size)
{
ring.buffer = buffer;
ring.size = size;
ring.head = 0;
ring.tail = 0;
}
/*
* \brief Add a CAN message to the specified ring buffer.
*
* \param ring - ring buffer to use.
* \param msg - message structure to add.
*
* \retval true if added, false if the ring is full.
*
*/
bool FlexCAN::addToRingBuffer (ringbuffer_t &ring, const CAN_message_t &msg)
{
uint16_t nextEntry;
nextEntry = (ring.head + 1) % ring.size;
/* check if the ring buffer is full */
if (nextEntry == ring.tail) {
return (false);
}