halpxa27xcounterm.nc

tinyos2.0版本驱动

/*
 * Copyright (c) 2005 Arched Rock Corporation 
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 *   Neither the name of the Arched Rock Corporation nor the names of its
 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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/** 
 * Implements a TOS 2.0 Counter on the PXA27x HPL. The PXA27x does not 
 * have an explicit overflow notification. We emulate one by using 
 * the associated match register set to 0. This requires we initialize
 * the counter to 1 to avoid a false notification at startup.
 * 
 *  @author Phil Buonadonna
 */
#include "Timer.h"

generic module HalPXA27xCounterM(typedef frequency_tag, uint8_t resolution) 
{
  provides {
    interface Init;
    interface Counter<frequency_tag,uint32_t> as Counter;
    interface LocalTime<frequency_tag> as LocalTime;
  }
  uses {
    interface Init as OSTInit;
    interface HplPXA27xOSTimer as OSTChnl;
  }
}

implementation
{
  command error_t Init.init() {

    call OSTInit.init(); 

    // Continue on match, Non-periodic, w/ given resolution
    atomic {
      call OSTChnl.setOMCR(OMCR_C | OMCR_P | OMCR_CRES(resolution));
      call OSTChnl.setOSMR(0);
      call OSTChnl.setOSCR(1);
      call OSTChnl.clearOSSRbit();
      call OSTChnl.setOIERbit(TRUE);
    }
    return SUCCESS;

  }
  
  async command uint32_t Counter.get() {
    uint32_t cntr;

    cntr = call OSTChnl.getOSCR();
    return cntr;
  }

  async command bool Counter.isOverflowPending() {
    bool flag;

    atomic flag = call OSTChnl.getOSSRbit();
    return flag;
  }

  async command void Counter.clearOverflow() {

    atomic call OSTChnl.clearOSSRbit();
  }

  async event void OSTChnl.fired() {
    call OSTChnl.clearOSSRbit();
    signal Counter.overflow();
    return;
  }

  async command uint32_t LocalTime.get() {
    uint32_t cntr;

    cntr = call OSTChnl.getOSCR();
    return cntr;
  }

  default async event void Counter.overflow() {
    return;
  }

}