xtmrctr.c

ucos_ii 在microblaze平台上的移植

/* $Id: xtmrctr.c,v 1.9 2002/06/14 21:59:35 linnj Exp $ */
/******************************************************************************
*
*       XILINX IS PROVIDING THIS DESIGN, CODE, OR INFORMATION "AS IS"
*       AS A COURTESY TO YOU, SOLELY FOR USE IN DEVELOPING PROGRAMS AND
*       SOLUTIONS FOR XILINX DEVICES.  BY PROVIDING THIS DESIGN, CODE,
*       OR INFORMATION AS ONE POSSIBLE IMPLEMENTATION OF THIS FEATURE,
*       APPLICATION OR STANDARD, XILINX IS MAKING NO REPRESENTATION
*       THAT THIS IMPLEMENTATION IS FREE FROM ANY CLAIMS OF INFRINGEMENT,
*       AND YOU ARE RESPONSIBLE FOR OBTAINING ANY RIGHTS YOU MAY REQUIRE
*       FOR YOUR IMPLEMENTATION.  XILINX EXPRESSLY DISCLAIMS ANY
*       WARRANTY WHATSOEVER WITH RESPECT TO THE ADEQUACY OF THE
*       IMPLEMENTATION, INCLUDING BUT NOT LIMITED TO ANY WARRANTIES OR
*       REPRESENTATIONS THAT THIS IMPLEMENTATION IS FREE FROM CLAIMS OF
*       INFRINGEMENT, IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
*       FOR A PARTICULAR PURPOSE.
*
*       (c) Copyright 2002 Xilinx Inc.
*       All rights reserved.
*
******************************************************************************/
/*****************************************************************************/
/**
*
* @file xtmrctr.c
*
* Contains required functions for the XTmrCtr driver.
*
* <pre>
* MODIFICATION HISTORY:
*
* Ver   Who  Date     Changes
* ----- ---- -------- -----------------------------------------------
* 1.00a ecm  08/16/01 First release
* 1.00b jhl  02/21/02 Repartitioned the driver for smaller files
* </pre>
*
******************************************************************************/

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

#include "xbasic_types.h"
#include "xstatus.h"
#include "xparameters.h"
#include "xtmrctr.h"
#include "xtmrctr_i.h"

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


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


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


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


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


/*****************************************************************************/
/**
*
* Initializes a specific timer/counter instance/driver. Initialize fields of
* the XTmrCtr structure, then reset the timer/counter
*
* @param    InstancePtr is a pointer to the XTmrCtr instance to be worked on.
* @param    DeviceId is the unique id of the device controlled by this XTmrCtr
*           component.  Passing in a device id associates the generic XTmrCtr
*           component to a specific device, as chosen by the caller or
*           application developer.
*
* @return
*
*   - XST_SUCCESS if initialization was successful
*   - XST_DEVICE_IS_STARTED if the device has already been started
*   - XST_DEVICE_NOT_FOUND if the device doesn't exist
*
* @note
*
* None.
*
******************************************************************************/
XStatus XTmrCtr_Initialize(XTmrCtr *InstancePtr, Xuint16 DeviceId)
{
    XTmrCtr_Config *TmrCtrConfigPtr;
    int TmrCtrNumber;
    Xuint32 StatusReg;

    XASSERT_NONVOID(InstancePtr != XNULL);

    /*
     * Lookup the device configuration in the temporary CROM table. Use this
     * configuration info down below when initializing this component.
     */
    TmrCtrConfigPtr = XTmrCtr_LookupConfig(DeviceId);

    if (TmrCtrConfigPtr == (XTmrCtr_Config *)XNULL)
    {
        return XST_DEVICE_NOT_FOUND;
    }

    /* Check each of the timer counters of the device, if any are already
     * running, then the device should not be initialized. This allows the user
     * to stop the device and reinitialize, but prevents a user from
     * inadvertently initializing.
     */
    for (TmrCtrNumber = 0; TmrCtrNumber < XTC_DEVICE_TIMER_COUNT; TmrCtrNumber++)
    {
        /*
         * read the current register contents and check if the timer counter
         * is started and running, note that the register read is not using
         * the base address in the instance so this is not destructive if
         * the timer counter is already started
         */
        StatusReg = XTimerCtr_mReadReg(TmrCtrConfigPtr->BaseAddress,
                                      TmrCtrNumber, XTC_TCSR_OFFSET);
        if (StatusReg & XTC_CSR_ENABLE_TMR_MASK)
        {
            return XST_DEVICE_IS_STARTED;
        }
    }

    /*
     * Set some default values, including setting the callback
     * handlers to stubs.
     */
    InstancePtr->BaseAddress = TmrCtrConfigPtr->BaseAddress;
    InstancePtr->Handler = XNULL;
    InstancePtr->CallBackRef = XNULL;

    /*
     * Clear the statistics for this driver
     */
    InstancePtr->Stats.Interrupts = 0;

    /* Initialize the registers of each timer/counter in the device */

    for (TmrCtrNumber = 0; TmrCtrNumber < XTC_DEVICE_TIMER_COUNT; TmrCtrNumber++)
    {
        /*
         * set the Compare register to 0
         */
        XTmrCtr_mWriteReg(InstancePtr->BaseAddress, TmrCtrNumber,
                           XTC_TLR_OFFSET, 0);
        /*
         * reset the timer and the interrupt, the reset bit will need to
         * be cleared after this
         */
        XTmrCtr_mWriteReg(InstancePtr->BaseAddress, TmrCtrNumber,
                           XTC_TCSR_OFFSET,
                           XTC_CSR_INT_OCCURED_MASK | XTC_CSR_LOAD_MASK);
        /*
         * set the control/status register to complete initialization by
         * clearing the reset bit which was just set
         */
        XTmrCtr_mWriteReg(InstancePtr->BaseAddress, TmrCtrNumber,
                           XTC_TCSR_OFFSET, 0);
    }

    /*
     * indicate the instance is ready to use, successfully initialized
     */
    InstancePtr->IsReady = XCOMPONENT_IS_READY;

    return XST_SUCCESS;
}

/*****************************************************************************/
/**
*
* Starts the specified timer counter of the device such that it starts running.
* The timer counter is reset before it is started and the reset value is
* loaded into the timer counter.
*
* If interrupt mode is specified in the options, it is necessary for the caller
* to connect the interrupt handler of the timer/counter to the interrupt source,
* typically an interrupt controller, and enable the interrupt within the
* interrupt controller.
*
* @param    InstancePtr is a pointer to the XTmrCtr instance to be worked on.
* @param    TmrCtrNumber is the timer counter of the device to operate on.
*           Each device may contain multiple timer counters. The timer number
*           is a zero based number with a range of
*           0 - (XTC_DEVICE_TIMER_COUNT - 1).
*
* @return
*
* None.
*
* @note
*
* None.
*
******************************************************************************/
void XTmrCtr_Start(XTmrCtr *InstancePtr, Xuint8 TmrCtrNumber)
{
    Xuint32 ControlStatusReg;

    XASSERT_VOID(InstancePtr != XNULL);
    XASSERT_VOID(TmrCtrNumber < XTC_DEVICE_TIMER_COUNT);
    XASSERT_VOID(InstancePtr->IsReady == XCOMPONENT_IS_READY);

    /*
     * read the current register contents such that only the necessary bits
     * of the register are modified in the following operations
     */
    ControlStatusReg = XTimerCtr_mReadReg(InstancePtr->BaseAddress,
                                         TmrCtrNumber, XTC_TCSR_OFFSET);
    /*
     * reset the timer counter such that it reloads from the compare register
     * and the interrupt is cleared simultaneously, the interrupt can only be
     * cleared after reset such that the interrupt condition is cleared
     */
    XTmrCtr_mWriteReg(InstancePtr->BaseAddress, TmrCtrNumber,
                       XTC_TCSR_OFFSET,
                       XTC_CSR_LOAD_MASK | XTC_CSR_INT_OCCURED_MASK);

    /*
     * remove the reset condition such that the timer counter starts running
     * with the value loaded from the compare register
     */
    XTmrCtr_mWriteReg(InstancePtr->BaseAddress, TmrCtrNumber,
                       XTC_TCSR_OFFSET,
                       ControlStatusReg | XTC_CSR_ENABLE_TMR_MASK);
}

/*****************************************************************************/
/**
*
* Stops the timer counter by disabling it.
*
* It is the callers' responsibility to disconnect the interrupt handler of the
* timer_counter from the interrupt source, typically an interrupt controller,
* and disable the interrupt within the interrupt controller.
*
* @param    InstancePtr is a pointer to the XTmrCtr instance to be worked on.
* @param    TmrCtrNumber is the timer counter of the device to operate on.
*           Each device may contain multiple timer counters. The timer number
*           is a zero based number with a range of
*           0 - (XTC_DEVICE_TIMER_COUNT - 1).
*
* @return
*
* None.
*
* @note
*
* None.
*