xcanps.c

自学ZedBoard：使用IP通过ARM PS访问FPGA（源代码）

/******************************************************************************
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******************************************************************************/
/*****************************************************************************/
/**
*
* @file xcanps.c
*
* Functions in this file are the minimum required functions for the XCanPs
* driver. See xcanps.h for a detailed description of the driver.
*
* @note 	None.
*
*
* <pre>
* MODIFICATION HISTORY:
*
* Ver   Who    Date	Changes
* ----- -----  -------- -----------------------------------------------
* 1.00a xd/sv  01/12/10 First release
* 1.01a bss    12/27/11 Added the APIs XCanPs_SetTxIntrWatermark and
* 			XCanPs_GetTxIntrWatermark.
* </pre>
*
******************************************************************************/

/***************************** Include Files *********************************/

#include "xcanps.h"

/************************** Constant Definitions *****************************/

/**************************** Type Definitions *******************************/

/***************** Macros (Inline Functions) Definitions *********************/

/************************** Variable Definitions *****************************/

/************************** Function Prototypes ******************************/

static void StubHandler(void);

/*****************************************************************************/
/*
*
* This function initializes a XCanPs instance/driver.
*
* The initialization entails:
* - Initialize all members of the XCanPs structure.
* - Reset the CAN device. The CAN device will enter Configuration Mode
*   immediately after the reset is finished.
*
* @param	InstancePtr is a pointer to the XCanPs instance.
* @param	ConfigPtr points to the XCanPs device configuration structure.
* @param	EffectiveAddr is the device base address in the virtual memory
*		address space. If the address translation is not used then the
*		physical address is passed.
*		Unexpected errors may occur if the address mapping is changed
*		after this function is invoked.
*
* @return	XST_SUCCESS always.
*
* @note		None.
*
******************************************************************************/
int XCanPs_CfgInitialize(XCanPs *InstancePtr, XCanPs_Config *ConfigPtr,
				u32 EffectiveAddr)
{

	Xil_AssertNonvoid(InstancePtr != NULL);
	Xil_AssertNonvoid(ConfigPtr != NULL);

	/*
	 * Set some default values for instance data, don't indicate the device
	 * is ready to use until everything has been initialized successfully.
	 */
	InstancePtr->IsReady = 0;
	InstancePtr->CanConfig.BaseAddr = EffectiveAddr;
	InstancePtr->CanConfig.DeviceId = ConfigPtr->DeviceId;

	/*
	 * Set all handlers to stub values, let user configure this data later.
	 */
	InstancePtr->SendHandler = (XCanPs_SendRecvHandler) StubHandler;
	InstancePtr->RecvHandler = (XCanPs_SendRecvHandler) StubHandler;
	InstancePtr->ErrorHandler = (XCanPs_ErrorHandler) StubHandler;
	InstancePtr->EventHandler = (XCanPs_EventHandler) StubHandler;

	/*
	 * Indicate the component is now ready to use.
	 */
	InstancePtr->IsReady = XIL_COMPONENT_IS_READY;

	/*
	 * Reset the device to get it into its initial state.
	 */
	XCanPs_Reset(InstancePtr);

	return XST_SUCCESS;
}

/*****************************************************************************/
/**
*
* This function resets the CAN device. Calling this function resets the device
* immediately, and any pending transmission or reception is terminated at once.
* Both Object Layer and Transfer Layer are reset. This function does not reset
* the Physical Layer. All registers are reset to the default values, and no
* previous status will be restored. TX FIFO, RX FIFO and TX High Priority
* Buffer are also reset.
*
* When a reset is required due to an internal error, the driver notifies the
* upper layer software of this need through the error status code or interrupts.
* The upper layer software is responsible for calling this Reset function and
* then re-configuring the device.
*
* The CAN device will be in Configuration Mode immediately after this function
* returns.
*
* @param	InstancePtr is a pointer to the XCanPs instance.
*
* @return	None.
*
* @note		None.
*
******************************************************************************/
void XCanPs_Reset(XCanPs *InstancePtr)
{
	Xil_AssertVoid(InstancePtr != NULL);
	Xil_AssertVoid(InstancePtr->IsReady == XIL_COMPONENT_IS_READY);

	XCanPs_WriteReg(InstancePtr->CanConfig.BaseAddr, XCANPS_SRR_OFFSET, \
			   XCANPS_SRR_SRST_MASK);
}

/****************************************************************************/
/**
*
* This routine returns the current operation mode of the CAN device.
*
* @param	InstancePtr is a pointer to the XCanPs instance.
*
* @return
* 		- XCANPS_MODE_CONFIG if the device is in Configuration Mode.
* 		- XCANPS_MODE_SLEEP if the device is in Sleep Mode.
* 		- XCANPS_MODE_NORMAL if the device is in Normal Mode.
* 		- XCANPS_MODE_LOOPBACK if the device is in Loop Back Mode.
* 		- XCANPS_MODE_SNOOP if the device is in Snoop Mode.
*
* @note		None.
*
*****************************************************************************/
u8 XCanPs_GetMode(XCanPs *InstancePtr)
{
	u32 StatusReg;

	Xil_AssertNonvoid(InstancePtr != NULL);
	Xil_AssertNonvoid(InstancePtr->IsReady == XIL_COMPONENT_IS_READY);

	StatusReg = XCanPs_GetStatus(InstancePtr);

	if (StatusReg & XCANPS_SR_CONFIG_MASK) {
		return XCANPS_MODE_CONFIG;

	} else if (StatusReg & XCANPS_SR_SLEEP_MASK) {
		return XCANPS_MODE_SLEEP;

	} else if (StatusReg & XCANPS_SR_NORMAL_MASK) {
		if (StatusReg & XCANPS_SR_SNOOP_MASK) {
			return XCANPS_MODE_SNOOP;
		} else {
			return XCANPS_MODE_NORMAL;
		}
	} else {
		/*
		 * If this line is reached, the device is in Loop Back Mode.
		 */
		return XCANPS_MODE_LOOPBACK;
	}
}

/*****************************************************************************/
/**
*
* This function allows the CAN device to enter one of the following operation
* modes:
*	- Configuration Mode: Pass in parameter XCANPS_MODE_CONFIG
*	- Sleep Mode: Pass in parameter XCANPS_MODE_SLEEP
*	- Normal Mode: Pass in parameter XCANPS_MODE_NORMAL
*	- Loop Back Mode: Pass in parameter XCANPS_MODE_LOOPBACK.
*	- Snoop Mode: Pass in parameter XCANPS_MODE_SNOOP.
*
* Read the xcanps.h file and device specification for detailed description of
* each operation mode.
*
* @param	InstancePtr is a pointer to the XCanPs instance.
* @param	OperationMode specify which operation mode to enter. Valid value
*		is any of XCANPS_MODE_* defined in xcanps.h. Multiple modes
*		can not be entered at the same time.
*
* @return	None.
*
* @note
*
* This function does NOT ensure CAN device enters the specified operation mode
* before it returns the control to the caller. The caller is responsible for
* checking current operation mode using XCanPs_GetMode().
*
******************************************************************************/
void XCanPs_EnterMode(XCanPs *InstancePtr, u8 OperationMode)
{
	u8 CurrentMode;

	Xil_AssertVoid(InstancePtr != NULL);
	Xil_AssertVoid(InstancePtr->IsReady == XIL_COMPONENT_IS_READY);
	Xil_AssertVoid((OperationMode == XCANPS_MODE_CONFIG) ||
			(OperationMode == XCANPS_MODE_SLEEP) ||
			(OperationMode == XCANPS_MODE_NORMAL) ||
			(OperationMode == XCANPS_MODE_LOOPBACK) ||
			(OperationMode == XCANPS_MODE_SNOOP));

	CurrentMode = XCanPs_GetMode(InstancePtr);

	/*
	 * If current mode is Normal Mode and the mode to enter is Sleep Mode,
	 * or if current mode is Sleep Mode and the mode to enter is Normal
	 * Mode, no transition through Configuration Mode is needed.
	 */
	if ((CurrentMode == XCANPS_MODE_NORMAL) &&
		(OperationMode == XCANPS_MODE_SLEEP)) {
		/*
		 * Normal Mode ---> Sleep Mode
		 */
		XCanPs_WriteReg(InstancePtr->CanConfig.BaseAddr,
				XCANPS_MSR_OFFSET, XCANPS_MSR_SLEEP_MASK);
		return;

	} else if ((CurrentMode == XCANPS_MODE_SLEEP) &&
		 (OperationMode == XCANPS_MODE_NORMAL)) {
		/*
		 * Sleep Mode ---> Normal Mode
		 */
		XCanPs_WriteReg(InstancePtr->CanConfig.BaseAddr,
					XCANPS_MSR_OFFSET, 0);
		return;
	}


	/*
	 * If the mode transition is not any of the two cases above, CAN must
	 * enter Configuration Mode before switching into the target operation
	 * mode.
	 */
	XCanPs_WriteReg(InstancePtr->CanConfig.BaseAddr,
				XCANPS_SRR_OFFSET, 0);

	/*
	 * Check if the device has entered Configuration Mode, if not, return to
	 * the caller.
	 */
	if (XCanPs_GetMode(InstancePtr) != XCANPS_MODE_CONFIG) {
		return;
	}

	switch (OperationMode) {
	case XCANPS_MODE_CONFIG:
		/*
		 * As CAN is in Configuration Mode already.
		 * Nothing is needed to be done here.
		 */
		break;

	case XCANPS_MODE_SLEEP:
		XCanPs_WriteReg(InstancePtr->CanConfig.BaseAddr,
				XCANPS_MSR_OFFSET, XCANPS_MSR_SLEEP_MASK);
		XCanPs_WriteReg(InstancePtr->CanConfig.BaseAddr,
				XCANPS_SRR_OFFSET, XCANPS_SRR_CEN_MASK);
		break;

	case XCANPS_MODE_NORMAL:
		XCanPs_WriteReg(InstancePtr->CanConfig.BaseAddr,
				XCANPS_MSR_OFFSET, 0);
		XCanPs_WriteReg(InstancePtr->CanConfig.BaseAddr,
				XCANPS_SRR_OFFSET, XCANPS_SRR_CEN_MASK);
		break;

	case XCANPS_MODE_LOOPBACK:
		XCanPs_WriteReg(InstancePtr->CanConfig.BaseAddr,
				XCANPS_MSR_OFFSET, XCANPS_MSR_LBACK_MASK);
		XCanPs_WriteReg(InstancePtr->CanConfig.BaseAddr,
				XCANPS_SRR_OFFSET, XCANPS_SRR_CEN_MASK);
		break;

	case XCANPS_MODE_SNOOP:
		XCanPs_WriteReg(InstancePtr->CanConfig.BaseAddr,
				XCANPS_MSR_OFFSET, XCANPS_MSR_SNOOP_MASK);
		XCanPs_WriteReg(InstancePtr->CanConfig.BaseAddr,
				XCANPS_SRR_OFFSET, XCANPS_SRR_CEN_MASK);
		break;

	}
}

/*****************************************************************************/
/**
*
* This function returns Status value from Status Register (SR). Use the
* XCANPS_SR_* constants defined in xcanps_hw.h to interpret the returned
* value.
*
* @param	InstancePtr is a pointer to the XCanPs instance.
*
* @return	The 32-bit value read from Status Register.
*
* @note		None.
*
******************************************************************************/
u32 XCanPs_GetStatus(XCanPs *InstancePtr)
{

	Xil_AssertNonvoid(InstancePtr != NULL);
	Xil_AssertNonvoid(InstancePtr->IsReady == XIL_COMPONENT_IS_READY);

	return XCanPs_ReadReg(InstancePtr->CanConfig.BaseAddr,
				XCANPS_SR_OFFSET);
}

/*****************************************************************************/
/**
*
* This function reads Receive and Transmit error counters.
*
* @param	InstancePtr is a pointer to the XCanPs instance.
* @param	RxErrorCount is a pointer to data in which the Receive Error
*		counter value is returned.
* @param	TxErrorCount is a pointer to data in which the Transmit Error
*		counter value is returned.
*
* @return	None.
*
* @note		None.
*
******************************************************************************/
void XCanPs_GetBusErrorCounter(XCanPs *InstancePtr, u8 *RxErrorCount,
				 u8 *TxErrorCount)
{
	u32 ErrorCount;

	Xil_AssertVoid(InstancePtr != NULL);
	Xil_AssertVoid(InstancePtr->IsReady == XIL_COMPONENT_IS_READY);
	Xil_AssertVoid(RxErrorCount != NULL);
	Xil_AssertVoid(TxErrorCount != NULL);