hal_api.c

这是motorola公司的powerpc芯片上的嵌入式linux上的驱动程序和测试程序

/***********************************************************************
 *
 * (C) Copyright 2002,12
 * 
 * Qi zhaoling 
 * All rights left.
 *
 *
 * a memory map API  for UT850GE
 *
 *
 * $Id: hal_api.c,v 1.1 2000/02/17 10:07:01 wd Exp $
 *
 ***********************************************************************/

#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>

#include "hal_api.h"


#undef	HAL_DEBUG

#ifdef	HAL_DEBUG
# define hal_debugk(fmt,args...)	printf(fmt ,##args)
#else
# define hal_debugk(fmt,args...)
#endif


int reg_devFd=0;


/*
*  return: 1 - W/R
           0 - readonly
          -1 - un-accessable
*/
int hal_reg_validate(U32 addr)
{
	return MEM_ACCESS_WR;
}

int hal_reg_module_init()
{
	if(!reg_devFd)
	{
		reg_devFd = open("/dev/mem_api",O_RDWR);
		if(reg_devFd < 0)
		{
			printf("Cann't open device: /dev/mem_api .\n");
			return -1;
		}
	}
	return 0;
}

void hal_reg_module_release()
{
	close(reg_devFd);
	return;
}

int hal_reg_read(U32 addr, U32 *value)
{
	U32 x;
	
	if(hal_reg_validate(addr) == MEM_ACCESS_OUT_RANGE)
		return MEM_ACCESS_OUT_RANGE;
		
	if(addr != lseek(reg_devFd, (off_t)addr, SEEK_SET) )
	{
		printf("hal lseek failed: %d\n",addr);
		return MEM_ACCESS_FAILED;
	}
	
	if(4 != read(reg_devFd,&x,4) )
	{
		printf("hal read failed\n");
		return MEM_ACCESS_FAILED;
	}
	*value = x;
	hal_debugk("hal read from register 0x%04x : 0x%04x \n", addr, x);
	return MEM_ACCESS_SUCCESS;	
}




int hal_reg_write(U32 addr, U32* value)
{
	
	if(hal_reg_validate(addr) == MEM_ACCESS_OUT_RANGE)
		return MEM_ACCESS_OUT_RANGE;
		
	if(hal_reg_validate(addr) == MEM_ACCESS_RO)
		return MEM_ACCESS_RO;	
			
	if(addr != lseek(reg_devFd, (off_t)addr, SEEK_SET) )
	{
		printf("hal lseek failed: %d\n",addr);
		return MEM_ACCESS_FAILED;
	}
	
	if(4 != write(reg_devFd,value,4) )
	{
		printf("hal read failed\n");
		return MEM_ACCESS_FAILED;
	}
	
	hal_debugk("hal write 0x%04x to register 0x%04x \n", value, addr);
	return MEM_ACCESS_SUCCESS;	
}

int hal_reg_BitSet(U32 addr, U32 bit)
{
   U32 data, bitmask;
   int ret;
   
   bitmask = ((U32)1) << bit;
   ret = hal_reg_read(addr, &data);
   
   if(ret < MEM_ACCESS_SUCCESS)
   	return ret;
   	
   data |= bitmask; 
   ret = hal_reg_write(addr, &data);
   
   return ret;	
}

int hal_reg_BitClear(U32 addr, U32 bit)
{
   U32 data, bitmask;
   int ret;
   
   bitmask = ((U32)1) << bit;
   ret = hal_reg_read(addr, &data);
   
   if(ret < MEM_ACCESS_SUCCESS)
   	return ret;
   	
   data &= (~bitmask); 
   ret = hal_reg_write(addr, &data);
   
   return ret;		
}