sam-t2/docs/mmi/mmiexample/mmiexample.C

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//
// OpenSPARC T2 Processor File: mmiexample.C
// Copyright (c) 2006 Sun Microsystems, Inc.  All Rights Reserved.
// DO NOT ALTER OR REMOVE COPYRIGHT NOTICES.
//
// The above named program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public
// License version 2 as published by the Free Software Foundation.
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// General Public License for more details.
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// ========== Copyright Header End ============================================
// mmiexample.C
// simple device model that uses the SAM MMI API.
// 2005.05.31

#include <stdio.h>
#include <sys/types.h>

#include "mmi.h"

extern "C" void mmiexample_instance_creator(const char * modname, const char * instancename);
extern "C" int mmiexample_access(uint32_t cpuid, void* obj, uint64_t paddr, mmi_bool_t wr, uint32_t size, uint64_t* buf, uint8_t bytemask);

// mmiexample - a simple device that returns monotonically increasing counter values
// store resets the counter

// "mmiexample" is instantiated using a simple sysconf directive:
// sysconf mmiexample example1 # no arguments


struct mmiexample_s {
  int counter;
}; // struct mmiexample_s


extern "C" void _init()
{
  mmi_register_instance_creator("example", mmiexample_instance_creator);
}


void mmiexample_instance_creator(const char * modname, const char * instance_name)
{
  printf("%s: Instantiating %s\n", modname, instance_name);

  // call mmi_argc() and mmi_argv() here to get device node arguments

  mmiexample_s * instance_data = new mmiexample_s;
  instance_data->counter = 0;

  // we currently support only one instance at a hardcoded physical address of 0xdeadbeef0
  mmi_map_physio(0xdeadbeef0, 8, (void *)instance_data, mmiexample_access);

} // example_instance_creator()


int mmiexample_access(uint32_t cpuid, void* obj, uint64_t paddr, mmi_bool_t wr, uint32_t size, uint64_t* buf, uint8_t bytemask)
{
  mmiexample_s * instance_data = (mmiexample_s *) obj;

  // should check args like paddr, size etc but for now we assume that a uint64_t is passed in *buf
  if (wr) {
    instance_data->counter = (int) *buf;
    return 0;
  } else {
    *buf = (uint64_t) (++ instance_data->counter);
    return 0;
  }
}