text: /******************************************************************************
  *
  * Copyright (C) 2010 - 2014 Xilinx, Inc.  All rights reserved.
  *
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  * of this software and associated documentation files (the "Software"), to deal
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  * furnished to do so, subject to the following conditions:
  *
  * The above copyright notice and this permission notice shall be included in
  * all copies or substantial portions of the Software.
  *
  * Use of the Software is limited solely to applications:
  * (a) running on a Xilinx device, or
  * (b) that interact with a Xilinx device through a bus or interconnect.
  *
  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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  * this Software without prior written authorization from Xilinx.
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  ******************************************************************************/
  /****************************************************************************/
  /**
  *
  * @file xuartps_intr.c
  * @addtogroup uartps_v2_1
  * @{
  *
  * This file contains the functions for interrupt handling
  *
  * <pre>
  * MODIFICATION HISTORY:
  *
  * Ver   Who    Date	Changes
  * ----- ------ -------- -----------------------------------------------
  * 1.00  drg/jz 01/13/10 First Release
  * </pre>
  *
  *****************************************************************************/
  
  /***************************** Include Files ********************************/
  
  #include "xuartps.h"
  
  /************************** Constant Definitions ****************************/
  
  /**************************** Type Definitions ******************************/
  
  /***************** Macros (Inline Functions) Definitions ********************/
  
  /************************** Function Prototypes *****************************/
  
  static void ReceiveDataHandler(XUartPs *InstancePtr);
  static void SendDataHandler(XUartPs *InstancePtr, u32 isrstatus);
  static void ReceiveErrorHandler(XUartPs *InstancePtr);
  static void ReceiveTimeoutHandler(XUartPs *InstancePtr);
  static void ModemHandler(XUartPs *InstancePtr);
  
  
  /* Internal function prototypes implemented in xuartps.c */
  extern unsigned int XUartPs_ReceiveBuffer(XUartPs *InstancePtr);
  extern unsigned int XUartPs_SendBuffer(XUartPs *InstancePtr);
  
  /************************** Variable Definitions ****************************/
  
  typedef void (*Handler)(XUartPs *InstancePtr);
  
  /****************************************************************************/
  /**
  *
  * This function gets the interrupt mask
  *
  * @param	InstancePtr is a pointer to the XUartPs instance.
  *
  * @return
  *		The current interrupt mask. The mask indicates which interupts
  *		are enabled.
  *
  * @note		None.
  *
  *****************************************************************************/
  u32 XUartPs_GetInterruptMask(XUartPs *InstancePtr)
  {
  	/*
  	 * Assert validates the input argument
  	 */
  	Xil_AssertNonvoid(InstancePtr != NULL);
  
  	/*
  	 * Read the Interrupt Mask register
  	 */
  	return (XUartPs_ReadReg(InstancePtr->Config.BaseAddress,
  			 XUARTPS_IMR_OFFSET));
  }
  
  /****************************************************************************/
  /**
  *
  * This function sets the interrupt mask.
  *
  * @param	InstancePtr is a pointer to the XUartPs instance
  * @param	Mask contains the interrupts to be enabled or disabled.
  *		A '1' enables an interupt, and a '0' disables.
  *
  * @return	None.
  *
  * @note		None.
  *
  *****************************************************************************/
  void XUartPs_SetInterruptMask(XUartPs *InstancePtr, u32 Mask)
  {
  	/*
  	 * Assert validates the input arguments
  	 */
  	Xil_AssertVoid(InstancePtr != NULL);
  
  	Mask &= XUARTPS_IXR_MASK;
  
  	/*
  	 * Write the mask to the IER Register
  	 */
  	XUartPs_WriteReg(InstancePtr->Config.BaseAddress,
  		 XUARTPS_IER_OFFSET, Mask);
  
  	/*
  	 * Write the inverse of the Mask to the IDR register
  	 */
  	XUartPs_WriteReg(InstancePtr->Config.BaseAddress,
  		 XUARTPS_IDR_OFFSET, (~Mask));
  
  }
  
  /****************************************************************************/
  /**
  *
  * This function sets the handler that will be called when an event (interrupt)
  * occurs that needs application's attention.
  *
  * @param	InstancePtr is a pointer to the XUartPs instance
  * @param	FuncPtr is the pointer to the callback function.
  * @param	CallBackRef is the upper layer callback reference passed back
  *		when the callback function is invoked.
  *
  * @return	None.
  *
  * @note
  *
  * There is no assert on the CallBackRef since the driver doesn't know what it
  * is (nor should it)
  *
  *****************************************************************************/
  void XUartPs_SetHandler(XUartPs *InstancePtr, XUartPs_Handler FuncPtr,
  		 void *CallBackRef)
  {
  	/*
  	 * Asserts validate the input arguments
  	 * CallBackRef not checked, no way to know what is valid
  	 */
  	Xil_AssertVoid(InstancePtr != NULL);
  	Xil_AssertVoid(FuncPtr != NULL);
  	Xil_AssertVoid(InstancePtr->IsReady == XIL_COMPONENT_IS_READY);
  
  	InstancePtr->Handler = FuncPtr;
  	InstancePtr->CallBackRef = CallBackRef;
  }
  
  /****************************************************************************/
  /**
  *
  * This function is the interrupt handler for the driver.
  * It must be connected to an interrupt system by the application such that it
  * can be called when an interrupt occurs.
  *
  * @param	InstancePtr contains a pointer to the driver instance
  *
  * @return	None.
  *
  * @note		None.
  *
  ******************************************************************************/
  void XUartPs_InterruptHandler(XUartPs *InstancePtr)
  {
  	u32 IsrStatus;
  
  	Xil_AssertVoid(InstancePtr != NULL);
  	Xil_AssertVoid(InstancePtr->IsReady == XIL_COMPONENT_IS_READY);
  
  	/*
  	 * Read the interrupt ID register to determine which
  	 * interrupt is active
  	 */
  	IsrStatus = XUartPs_ReadReg(InstancePtr->Config.BaseAddress,
  				   XUARTPS_IMR_OFFSET);
  
  	IsrStatus &= XUartPs_ReadReg(InstancePtr->Config.BaseAddress,
  				   XUARTPS_ISR_OFFSET);
  
  	/*
  	 * Dispatch an appropiate handler.
  	 */
  	if(0 != (IsrStatus & (XUARTPS_IXR_RXOVR | XUARTPS_IXR_RXEMPTY |
  				 XUARTPS_IXR_RXFULL))) {
  		/* Recieved data interrupt */
  		ReceiveDataHandler(InstancePtr);
  	}
  
  	if(0 != (IsrStatus & (XUARTPS_IXR_TXEMPTY | XUARTPS_IXR_TXFULL))) {
  		/* Transmit data interrupt */
  		SendDataHandler(InstancePtr, IsrStatus);
  	}
  
  	if(0 != (IsrStatus & (XUARTPS_IXR_OVER | XUARTPS_IXR_FRAMING |
  				XUARTPS_IXR_PARITY))) {
  		/* Recieved Error Status interrupt */
  		ReceiveErrorHandler(InstancePtr);
  	}
  
  	if(0 != (IsrStatus & XUARTPS_IXR_TOUT )) {
  		/* Recieved Timeout interrupt */
  		ReceiveTimeoutHandler(InstancePtr);
  	}
  
  	if(0 != (IsrStatus & XUARTPS_IXR_DMS)) {
  		/* Modem status interrupt */
  		ModemHandler(InstancePtr);
  	}
  
  	/*
  	 * Clear the interrupt status.
  	 */
  	XUartPs_WriteReg(InstancePtr->Config.BaseAddress, XUARTPS_ISR_OFFSET,
  		IsrStatus);
  
  }
  
  /****************************************************************************/
  /*
  *
  * This function handles interrupts for receive errors which include
  * overrun errors, framing errors, parity errors, and the break interrupt.
  *
  * @param	InstancePtr is a pointer to the XUartPs instance.
  *
  * @return	None.
  *
  * @note		None.
  *
  *****************************************************************************/
  static void ReceiveErrorHandler(XUartPs *InstancePtr)
  {
  	/*
  	 * If there are bytes still to be received in the specified buffer
  	 * go ahead and receive them. Removing bytes from the RX FIFO will
  	 * clear the interrupt.
  	 */
  	if (InstancePtr->ReceiveBuffer.RemainingBytes != 0) {
  		XUartPs_ReceiveBuffer(InstancePtr);
  	}
  
  	/*
  	 * Call the application handler to indicate that there is a receive
  	 * error or a break interrupt, if the application cares about the
  	 * error it call a function to get the last errors.
  	 */
  	InstancePtr->Handler(InstancePtr->CallBackRef,
  				XUARTPS_EVENT_RECV_ERROR,
  				(InstancePtr->ReceiveBuffer.RequestedBytes -
  				InstancePtr->ReceiveBuffer.RemainingBytes));
  
  }
  /****************************************************************************/
  /**
  *
  * This function handles the receive timeout interrupt. This interrupt occurs
  * whenever a number of bytes have been present in the RX FIFO and the receive
  * data line has been idle for at lease 4 or more character times, (the timeout
  * is set using XUartPs_SetrecvTimeout() function).
  *
  * @param	InstancePtr is a pointer to the XUartPs instance
  *
  * @return	None.
  *
  * @note		None.
  *
  *****************************************************************************/
  static void ReceiveTimeoutHandler(XUartPs *InstancePtr)
  {
  	u32 Event;
  
  	/*
  	 * If there are bytes still to be received in the specified buffer
  	 * go ahead and receive them. Removing bytes from the RX FIFO will
  	 * clear the interrupt.
  	 */
  	if (InstancePtr->ReceiveBuffer.RemainingBytes != 0) {
  		XUartPs_ReceiveBuffer(InstancePtr);
  	}
  
  	/*
  	 * If there are no more bytes to receive then indicate that this is
  	 * not a receive timeout but the end of the buffer reached, a timeout
  	 * normally occurs if # of bytes is not divisible by FIFO threshold,
  	 * don't rely on previous test of remaining bytes since receive
  	 * function updates it
  	 */
  	if (InstancePtr->ReceiveBuffer.RemainingBytes != 0) {
  		Event = XUARTPS_EVENT_RECV_TOUT;
  	} else {
  		Event = XUARTPS_EVENT_RECV_DATA;
  	}
  
  	/*
  	 * Call the application handler to indicate that there is a receive
  	 * timeout or data event
  	 */
  	InstancePtr->Handler(InstancePtr->CallBackRef, Event,
  				 InstancePtr->ReceiveBuffer.RequestedBytes -
  				 InstancePtr->ReceiveBuffer.RemainingBytes);
  
  }
  /****************************************************************************/
  /**
  *
  * This function handles the interrupt when data is in RX FIFO.
  *
  * @param	InstancePtr is a pointer to the XUartPs instance
  *
  * @return	None.
  *
  * @note		None.
  *
  *****************************************************************************/
  static void ReceiveDataHandler(XUartPs *InstancePtr)
  {
  	/*
  	 * If there are bytes still to be received in the specified buffer
  	 * go ahead and receive them. Removing bytes from the RX FIFO will
  	 * clear the interrupt.
  	 */
  	 if (InstancePtr->ReceiveBuffer.RemainingBytes != 0) {
  		XUartPs_ReceiveBuffer(InstancePtr);
  	}
  
  
  	/* If the last byte of a message was received then call the application
  	 * handler, this code should not use an else from the previous check of
  	 * the number of bytes to receive because the call to receive the buffer
  	 * updates the bytes ramained
  	 */
  	if (InstancePtr->ReceiveBuffer.RemainingBytes == 0) {
  		InstancePtr->Handler(InstancePtr->CallBackRef,
  				XUARTPS_EVENT_RECV_DATA,
  				(InstancePtr->ReceiveBuffer.RequestedBytes -
  				InstancePtr->ReceiveBuffer.RemainingBytes));
  	}
  
  }
  
  /****************************************************************************/
  /**
  *
  * This function handles the interrupt when data has been sent, the transmit
  * FIFO is empty (transmitter holding register).
  *
  * @param	InstancePtr is a pointer to the XUartPs instance
  * @param	IsrStatus is the register value for channel status register
  *
  * @return	None.
  *
  * @note		None.
  *
  *****************************************************************************/
  static void SendDataHandler(XUartPs *InstancePtr, u32 IsrStatus)
  {
  
  	/*
  	 * If there are not bytes to be sent from the specified buffer then disable
  	 * the transmit interrupt so it will stop interrupting as it interrupts
  	 * any time the FIFO is empty
  	 */
  	if (InstancePtr->SendBuffer.RemainingBytes == 0) {
  		XUartPs_WriteReg(InstancePtr->Config.BaseAddress,
  				XUARTPS_IDR_OFFSET,
  				(XUARTPS_IXR_TXEMPTY | XUARTPS_IXR_TXFULL));
  
  		/* Call the application handler to indicate the sending is done */
  		InstancePtr->Handler(InstancePtr->CallBackRef,
  					XUARTPS_EVENT_SENT_DATA,
  					InstancePtr->SendBuffer.RequestedBytes -
  					InstancePtr->SendBuffer.RemainingBytes);
  	}
  
  	/*
  	 * If TX FIFO is empty, send more.
  	 */
  	else if(IsrStatus & XUARTPS_IXR_TXEMPTY) {
  		XUartPs_SendBuffer(InstancePtr);
  	}
  
  }
  
  /****************************************************************************/
  /**
  *
  * This function handles modem interrupts.  It does not do any processing
  * except to call the application handler to indicate a modem event.
  *
  * @param	InstancePtr is a pointer to the XUartPs instance
  *
  * @return	None.
  *
  * @note		None.
  *
  *****************************************************************************/
  static void ModemHandler(XUartPs *InstancePtr)
  {
  	u32 MsrRegister;
  
  	/*
  	 * Read the modem status register so that the interrupt is acknowledged
  	 * and it can be passed to the callback handler with the event
  	 */
  	MsrRegister = XUartPs_ReadReg(InstancePtr->Config.BaseAddress,
  			  XUARTPS_MODEMSR_OFFSET);
  
  	/*
  	 * Call the application handler to indicate the modem status changed,
  	 * passing the modem status and the event data in the call
  	 */
  	InstancePtr->Handler(InstancePtr->CallBackRef,
  				  XUARTPS_EVENT_MODEM,
  				  MsrRegister);
  
  }
  
  /** @} */
  