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*
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******************************************************************************/
/****************************************************************************/
/**
*
* @file xcan_intr_example.c
*
* Contains an example of how to use the XCan driver directly. The example here
* shows using the driver/device in interrupt mode.
*
* @note
*
* This code assumes that Xilinx interrupt controller (XIntc) is used in the
* system to forward the CAN device interrupt output to the processor and no
* operating system is being used.
*
* The Baud Rate Prescaler Register (BRPR) and Bit Timing Register (BTR)
* are setup such that CAN baud rate equals 40Kbps, assuming that the
* the CAN clock is 24MHz. The user needs to modify these values based on
* the desired baud rate and the CAN clock frequency. For more information
* see the CAN 2.0A, CAN 2.0B, ISO 11898-1 specifications.
*
* <pre>
* MODIFICATION HISTORY:
*
* Ver Who Date Changes
* ----- ----- -------- -----------------------------------------------
* 1.00a xd/sv 01/12/09 First release
* 2.00a ktn 10/22/09 Updated to use the HAL APIs/macros.
* The macros have been renamed to remove _m from the
* name.
* 2.00a bss 01/11/11 Updated the example to be used with the SCUGIC in
* Zynq.
* 2.00a bss 01/16/12 Updated the example to fix CR 694533,
* replaced INTC_DEVID with INTC_DEVICE_ID.
* </pre>
*
******************************************************************************/
/***************************** Include Files *********************************/
#include "xcan.h"
#include "xparameters.h"
#include "xstatus.h"
#include "xil_exception.h"
#ifdef XPAR_INTC_0_DEVICE_ID
#include "xintc.h"
#include <stdio.h>
#else /* SCU GIC */
#include "xscugic.h"
#include "xil_printf.h"
#endif
/************************** Constant Definitions *****************************/
/*
* The following constants map to the XPAR parameters created in the
* xparameters.h file. They are defined here such that a user can easily
* change all the needed parameters in one place.
*/
#define CAN_DEVICE_ID XPAR_CAN_0_DEVICE_ID
#define CAN_INTR_VEC_ID XPAR_INTC_0_CAN_0_VEC_ID
#ifdef XPAR_INTC_0_DEVICE_ID
#define INTC_DEVICE_ID XPAR_INTC_0_DEVICE_ID
#else
#define INTC_DEVICE_ID XPAR_SCUGIC_SINGLE_DEVICE_ID
#endif /* XPAR_INTC_0_DEVICE_ID */
/* Maximum CAN frame length in word */
#define XCAN_MAX_FRAME_SIZE_IN_WORDS (XCAN_MAX_FRAME_SIZE / sizeof(u32))
#define FRAME_DATA_LENGTH 8 /* Frame Data field length */
/*
* Message Id Constant.
*/
#define TEST_MESSAGE_ID 2650
/*
* The Baud Rate Prescaler Register (BRPR) and Bit Timing Register (BTR)
* are setup such that CAN baud rate equals 40Kbps, assuming that the
* the CAN clock is 24MHz. The user needs to modify these values based on
* the desired baud rate and the CAN clock frequency. For more information
* see the CAN 2.0A, CAN 2.0B, ISO 11898-1 specifications.
*/
#define TEST_BRPR_BAUD_PRESCALAR 29
#define TEST_BTR_SYNCJUMPWIDTH 3
#define TEST_BTR_SECOND_TIMESEGMENT 2
#define TEST_BTR_FIRST_TIMESEGMENT 15
#ifdef XPAR_INTC_0_DEVICE_ID
#define INTC XIntc
#define INTC_HANDLER XIntc_InterruptHandler
#else
#define INTC XScuGic
#define INTC_HANDLER XScuGic_InterruptHandler
#endif /* XPAR_INTC_0_DEVICE_ID */
/**************************** Type Definitions *******************************/
/***************** Macros (Inline Functions) Definitions *********************/
/************************** Function Prototypes ******************************/
static int XCanIntrExample(u16 DeviceId);
static void Config(XCan *InstancePtr);
static void SendFrame(XCan *InstancePtr);
static void SendHandler(void *CallBackRef);
static void RecvHandler(void *CallBackRef);
static void ErrorHandler(void *CallBackRef, u32 ErrorMask);
static void EventHandler(void *CallBackRef, u32 Mask);
static int SetupInterruptSystem(XCan *InstancePtr);
/************************** Variable Definitions *****************************/
/*
* Allocate an instance of the XCan driver
*/
static XCan Can;
/*
* Buffers to hold frames to send and receive. These are declared as global so
* that they are not on the stack.
* These buffers need to be 32-bit aligned
*/
static u32 TxFrame[XCAN_MAX_FRAME_SIZE_IN_WORDS];
static u32 RxFrame[XCAN_MAX_FRAME_SIZE_IN_WORDS];
/*
* Shared variables used to test the callbacks.
*/
volatile static int LoopbackError; /* Asynchronous error occurred */
volatile static int RecvDone; /* Received a frame */
volatile static int SendDone; /* Frame was sent successfully */
/*****************************************************************************/
/**
*
* This function is the main function of the Can interrupt example.
*
* @param None.
*
* @return
* - XST_SUCCESS if the example has completed successfully.
* - XST_FAILURE if the example has failed.
*
* @note None.
*
*****************************************************************************/
int main()
{
/*
* Run the Can interrupt example.
*/
if (XCanIntrExample(CAN_DEVICE_ID)) {
return XST_FAILURE;
}
return XST_SUCCESS;
}
/*****************************************************************************/
/**
*
* The main entry point for showing the XCan driver in interrupt mode.
* The example configures the device for internal loopback mode, then
* sends a CAN frame and receives the same CAN frame.
*
* @param DeviceId contains the CAN device ID.
*
* @return XST_SUCCESS if successful, otherwise driver-specific error code.
*
* @note If the device is not working correctly, this function may enter
* an infinite loop and will never return to the caller.
*
******************************************************************************/
static int XCanIntrExample(u16 DeviceId)
{
int Status;
/*
* Initialize the XCan driver.
*/
Status = XCan_Initialize(&Can, DeviceId);
if (Status != XST_SUCCESS) {
return XST_FAILURE;
}
/*
* Run self-test on the device, which verifies basic sanity of the
* device and the driver.
*/
Status = XCan_SelfTest(&Can);
if (Status != XST_SUCCESS) {
return XST_FAILURE;
}
/*
* Configure the CAN device.
*/
Config(&Can);
/*
* Set interrupt handlers.
*/
XCan_SetHandler(&Can, XCAN_HANDLER_SEND,
(void *)SendHandler, (void *)&Can);
XCan_SetHandler(&Can, XCAN_HANDLER_RECV,
(void *)RecvHandler, (void *)&Can);
XCan_SetHandler(&Can, XCAN_HANDLER_ERROR,
(void *)ErrorHandler, (void *)&Can);
XCan_SetHandler(&Can, XCAN_HANDLER_EVENT,
(void *)EventHandler, (void *)&Can);
/*
* Initialize flags.
*/
SendDone = FALSE;
RecvDone = FALSE;
LoopbackError = FALSE;
/*
* Connect to the interrupt controller.
*/
Status = SetupInterruptSystem(&Can);
if (Status != XST_SUCCESS) {
return XST_FAILURE;
}
/*
* Enable all interrupts in CAN device.
*/
XCan_InterruptEnable(&Can, XCAN_IXR_ALL);
/*
* Enter Loop Back Mode.
*/
XCan_EnterMode(&Can, XCAN_MODE_LOOPBACK);
while(XCan_GetMode(&Can) != XCAN_MODE_LOOPBACK);
/*
* Loop back a frame. The RecvHandler is expected to handle
* the frame reception.
*/
SendFrame(&Can); /* Send a frame */
/*
* Wait here until both sending and reception have been completed.
*/
while ((SendDone != TRUE) || (RecvDone != TRUE));
/*
* Check for errors found in the callbacks.
*/
if (LoopbackError == TRUE) {
return XST_LOOPBACK_ERROR;
}
return XST_SUCCESS;
}
/*****************************************************************************/
/**
*
* This function configures CAN device. Baud Rate Prescaler Register (BRPR) and
* Bit Timing Register (BTR) are set in this function.
*
* @param InstancePtr is a pointer to the driver instance
*
* @return None.
*
* @note If the CAN device is not working correctly, this function may
* enter an infinite loop and will never return to the caller.
*
******************************************************************************/
static void Config(XCan *InstancePtr)
{
/*
* Enter Configuration Mode if the device is not currently in
* Configuration Mode.
*/
XCan_EnterMode(InstancePtr, XCAN_MODE_CONFIG);
while(XCan_GetMode(InstancePtr) != XCAN_MODE_CONFIG);
/*
* Setup Baud Rate Prescaler Register (BRPR) and
* Bit Timing Register (BTR) such that CAN baud rate equals 40Kbps,
* given the CAN clock frequency equal to 24MHz.
*/
XCan_SetBaudRatePrescaler(InstancePtr, TEST_BRPR_BAUD_PRESCALAR);
XCan_SetBitTiming(InstancePtr, TEST_BTR_SYNCJUMPWIDTH,
TEST_BTR_SECOND_TIMESEGMENT,
TEST_BTR_FIRST_TIMESEGMENT);
}
/*****************************************************************************/
/**
*
* Send a CAN frame.
*
* @param InstancePtr is a pointer to the driver instance.
*
* @return None.
*
* @note None.
*
******************************************************************************/
static void SendFrame(XCan *InstancePtr)
{
u8 *FramePtr;
int Index;
int Status;
/*
* Create correct values for Identifier and Data Length Code Register.
*/
TxFrame[0] = XCan_CreateIdValue(TEST_MESSAGE_ID, 0, 0, 0, 0);
TxFrame[1] = XCan_CreateDlcValue(FRAME_DATA_LENGTH);
/*
* Now fill in the data field with known values so we can verify them
* on receive.
*/
FramePtr = (u8 *)(&TxFrame[2]);
for (Index = 0; Index < FRAME_DATA_LENGTH; Index++) {
*FramePtr++ = (u8)Index;
}
/*
* Now wait until the TX FIFO is not full and send the frame.
*/
while (XCan_IsTxFifoFull(InstancePtr) == TRUE);
Status = XCan_Send(InstancePtr, TxFrame);
if (Status != XST_SUCCESS) {
/* The frame could not be sent successfully */
LoopbackError = TRUE;
SendDone = TRUE;
RecvDone = TRUE;
}
}
/*****************************************************************************/
/**
*
* Callback function (called from interrupt handler) to handle confirmation of
* transmit events when in interrupt mode.
*
* @param CallBackRef is the callback reference passed from the interrupt
* handler, which in our case is a pointer to the driver instance.
*
* @return None.
*
* @note This function is called by the driver within interrupt context.
*
******************************************************************************/
static void SendHandler(void *CallBackRef)
{
/*
* The frame was sent successfully. Notify the task context.
*/
SendDone = TRUE;
}
/*****************************************************************************/
/**
*
* Callback function (called from interrupt handler) to handle frames received in
* interrupt mode. This function is called once per frame received.
* The driver's receive function is called to read the frame from RX FIFO.
*
* @param CallBackRef is the callback reference passed from the interrupt
* handler, which in our case is a pointer to the device instance.
*
* @return None.
*
* @note This function is called by the driver within interrupt context.
*
******************************************************************************/
static void RecvHandler(void *CallBackRef)
{
XCan *CanPtr = (XCan *)CallBackRef;
int Status;
int Index;
u8 *FramePtr;
Status = XCan_Recv(CanPtr, RxFrame);
if (Status != XST_SUCCESS) {
LoopbackError = TRUE;
RecvDone = TRUE;
return;
}
/*
* Verify Identifier and Data Length Code.
*/
if (RxFrame[0] != XCan_CreateIdValue(TEST_MESSAGE_ID, 0, 0, 0, 0)) {
LoopbackError = TRUE;
RecvDone = TRUE;
return;
}
if (RxFrame[1] != XCan_CreateDlcValue(FRAME_DATA_LENGTH)) {
LoopbackError = TRUE;
RecvDone = TRUE;
return;
}
/*
* Verify Data field contents.
*/
FramePtr = (u8 *)(&RxFrame[2]);
for (Index = 0; Index < FRAME_DATA_LENGTH; Index++){
if (*FramePtr++ != (u8)Index) {
LoopbackError = TRUE;
break;
}
}
RecvDone = TRUE;
}
/*****************************************************************************/
/**
*
* Callback function (called from interrupt handler) to handle error interrupt.
* Error code read from Error Status register is passed into this function
*
* @param CallBackRef is the callback reference passed from the interrupt
* handler, which in our case is a pointer to the driver instance.
* @param ErrorMask is a bit mask indicating the cause of the error. Its
* value equals 'OR'ing one or more XCAN_ESR_* defined in xcan_l.h
*
* @return None.
*
* @note This function is called by the driver within interrupt context.
*
******************************************************************************/
static void ErrorHandler(void *CallBackRef, u32 ErrorMask)
{
XCan *CanPtr = (XCan *)CallBackRef;
if(ErrorMask & XCAN_ESR_ACKER_MASK) {
/*
* ACK Error handling code should be put here.
*/
}
if(ErrorMask & XCAN_ESR_BERR_MASK) {
/*
* Bit Error handling code should be put here.
*/
}
if(ErrorMask & XCAN_ESR_STER_MASK) {
/*
* Stuff Error handling code should be put here.
*/
}
if(ErrorMask & XCAN_ESR_FMER_MASK) {
/*
* Form Error handling code should be put here.
*/
}
if(ErrorMask & XCAN_ESR_CRCER_MASK) {
/*
* CRC Error handling code should be put here.
*/
}
/*
* Set the shared variables.
*/
LoopbackError = TRUE;
RecvDone = TRUE;
SendDone = TRUE;
}
/*****************************************************************************/
/**
*
* Callback function (called from interrupt handler) to handle the following
* interrupts:
* - XCAN_IXR_BSOFF_MASK: Bus Off Interrupt
* - XCAN_IXR_RXOFLW_MASK: RX FIFO Overflow Interrupt
* - XCAN_IXR_RXUFLW_MASK: RX FIFO Underflow Interrupt
* - XCAN_IXR_TXBFLL_MASK: TX High Priority Buffer Full Interrupt
* - XCAN_IXR_TXFLL_MASK: TX FIFO Full Interrupt
* - XCAN_IXR_WKUP_MASK: Wake up Interrupt
* - XCAN_IXR_SLP_MASK: Sleep Interrupt
* - XCAN_IXR_ARBLST_MASK: Arbitration Lost Interrupt
*
* Please feel free to change this function to meet specific application needs.
*
* @param CallBackRef is the callback reference passed from the interrupt
* handler, which in our case is a pointer to the driver instance.
* @param IntrMask is a bit mask indicating pending interrupts. Its value
* equals 'OR'ing one or more of the XCAN_IXR_*_MASK value(s)
* mentioned above.
*
* @return None.
*
* @note This function is called by the driver within interrupt context.
*
******************************************************************************/
static void EventHandler(void *CallBackRef, u32 IntrMask)
{
XCan *CanPtr = (XCan *)CallBackRef;
if (IntrMask & XCAN_IXR_BSOFF_MASK) { /* Enter Bus off status */
/*
* Entering Bus off status interrupt requires
* the CAN device be reset and re-configurated.
*/
XCan_Reset(CanPtr);
Config(CanPtr);
return;
}
if(IntrMask & XCAN_IXR_RXOFLW_MASK) { /* RX FIFO Overflow Interrupt */
/*
* Code to handle RX FIFO Overflow
* Interrupt should be put here.
*/
}
if(IntrMask & XCAN_IXR_RXUFLW_MASK) { /* RX FIFO Underflow Interrupt */
/*
* Code to handle RX FIFO Underflow
* Interrupt should be put here.
*/
}
if(IntrMask & XCAN_IXR_TXBFLL_MASK) { /* TX High Priority Full Intr */
/*
* Code to handle TX High Priority Buffer Full
* Interrupt should be put here.
*/
}
if(IntrMask & XCAN_IXR_TXFLL_MASK) { /* TX FIFO Full Interrupt */
/*
* Code to handle TX FIFO Full
* Interrupt should be put here.
*/
}
if (IntrMask & XCAN_IXR_WKUP_MASK) { /* Wake up from sleep mode */
/*
* Code to handle Wake up from sleep mode
* Interrupt should be put here.
*/
}
if (IntrMask & XCAN_IXR_SLP_MASK) { /* Enter sleep mode */
/*
* Code to handle Enter sleep mode
* Interrupt should be put here.
*/
}
if (IntrMask & XCAN_IXR_ARBLST_MASK) { /* Lost bus arbitration */
/*
* Code to handle Lost bus arbitration
* Interrupt should be put here.
*/
}
}
/*****************************************************************************/
/**
*
* This function sets up the interrupt system so interrupts can occur for the
* CAN. This function is application-specific since the actual system may or
* may not have an interrupt controller. The CAN could be directly connected
* to a processor without an interrupt controller. The user should modify this
* function to fit the application.
*
* @para InstancePtr is a pointer to the instance of the CAN
* which is going to be connected to the interrupt controller.
*
* @return XST_SUCCESS if successful, otherwise XST_FAILURE.
*
* @note None.
*
****************************************************************************/
static int SetupInterruptSystem(XCan *InstancePtr)
{
static INTC InterruptController;
int Status;
#ifdef XPAR_INTC_0_DEVICE_ID
/*
* Initialize the interrupt controller driver so that it's ready to use.
* INTC_DEVICE_ID specifies the XINTC device ID that is generated in
* xparameters.h.
*/
Status = XIntc_Initialize(&InterruptController, INTC_DEVICE_ID);
if (Status != XST_SUCCESS) {
return XST_FAILURE;
}
/*
* Connect the device driver handler that will be called when an interrupt
* for the device occurs, the device driver handler performs the specific
* interrupt processing for the device.
*/
Status = XIntc_Connect(&InterruptController,
CAN_INTR_VEC_ID,
(XInterruptHandler)XCan_IntrHandler,
InstancePtr);
if (Status != XST_SUCCESS) {
return XST_FAILURE;
}
/*
* Start the interrupt controller so interrupts are enabled for all
* devices that cause interrupts. Specify real mode so that the CAN
* can cause interrupts through the interrupt controller.
*/
Status = XIntc_Start(&InterruptController, XIN_REAL_MODE);
if (Status != XST_SUCCESS){
return XST_FAILURE;
}
/*
* Enable the interrupt for the CAN.
*/
XIntc_Enable(&InterruptController, CAN_INTR_VEC_ID);
#else /* SCUGIC */
XScuGic_Config *IntcConfig;
/*
* Initialize the interrupt controller driver so that it is ready to
* use.
*/
IntcConfig = XScuGic_LookupConfig(INTC_DEVICE_ID);
if (NULL == IntcConfig) {
return XST_FAILURE;
}
Status = XScuGic_CfgInitialize(&InterruptController, IntcConfig,
IntcConfig->CpuBaseAddress);
if (Status != XST_SUCCESS) {
return XST_FAILURE;
}
XScuGic_SetPriorityTriggerType(&InterruptController, CAN_INTR_VEC_ID,
0xA0, 0x3);
/*
* Connect the interrupt handler that will be called when an
* interrupt occurs for the device.
*/
Status = XScuGic_Connect(&InterruptController, CAN_INTR_VEC_ID,
(Xil_ExceptionHandler)XCan_IntrHandler,
InstancePtr);
if (Status != XST_SUCCESS) {
return Status;
}
/*
* Enable the interrupt for the Can device.
*/
XScuGic_Enable(&InterruptController, CAN_INTR_VEC_ID);
#endif
/*
* Initialize the exception table.
*/
Xil_ExceptionInit();
/*
* Register the interrupt controller handler with the exception table.
*/
Xil_ExceptionRegisterHandler(XIL_EXCEPTION_ID_INT,
(Xil_ExceptionHandler)INTC_HANDLER,
&InterruptController);
/*
* Enable exceptions.
*/
Xil_ExceptionEnable();
return XST_SUCCESS;
}