Re: Howto read I2C on MPC5200 Lite

[Matthias Fechner <idefix@fechner.net>]

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Hi,

* Matthias Fechner <idefix@fechner.net> [10-03-07 00:42]:
> It seems now that everything works fine. I will check it for the next
> days. And will give some feedback.

ok, I checked now the driver some time at it failed. So it seems that
that the patch had not solved the problem.

I have attached the programm to check it.

I changed the time to 2 seconds but that didn't help.

Best regards,
Matthias

-- 

"Programming today is a race between software engineers striving to
build bigger and better idiot-proof programs, and the universe trying to
produce bigger and better idiots. So far, the universe is winning." --
Rich Cook

[-- Attachment #2: readMax6633.c --]
[-- Type: text/x-csrc, Size: 2176 bytes --]

/* read the data from max6633 */

#include <errno.h>
#include <string.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include "i2c-dev.h"
#include "version.h"

static __inline__ unsigned short swap_bytes(unsigned short val)
{
   return(val >> 8) | (val << 8);
}

int main(void)
{
   int res,address,file;
   char filename[20];
   unsigned short temp;
   long funcs;
   int i2cbus;
   int errorCount,successfullCount;
   errorCount=successfullCount=0;
   i2cbus=1;
   address=0x40;
   
   sprintf(filename,"/dev/i2c-%d",i2cbus);
   if((file=open(filename,O_RDWR))<0)
   {
      fprintf(stderr,"Error: could not open file %s: %s\n",filename,strerror(errno));
      exit(1);
   }
   
   /* check adapter functionality */
   if(ioctl(file,I2C_FUNCS,&funcs) < 0)
   {
      fprintf(stderr, "Error: could not get the adapter functionality matrix: %s\n",strerror(errno));
      goto ERROR0;
   }
   if(!(funcs & I2C_FUNC_SMBUS_READ_BYTE_DATA))
   {
      fprintf(stderr,"Error: Adapter for i2cbus %d",i2cbus);
      fprintf(stderr," does not have byte read capability\n");
      goto ERROR0;
   }
   if(!(funcs & I2C_FUNC_SMBUS_READ_WORD_DATA))
   {
      fprintf(stderr,"Error: Adapter for i2cbus %d",i2cbus);
      fprintf(stderr," does not have word read capability\n");
      goto ERROR0;
   }
      
   
   /* use FORCE so that we can look at registers even when a driver
      is also running */
   if(ioctl(file,I2C_SLAVE,address) <0)
   {
      fprintf(stderr,"Error: Could not set address to %d: %s\n",address, strerror(errno));
      goto ERROR0;
   }
   
   fprintf(stderr,"Read with word_data\n");
   while(1)
   {
      
      temp=res=i2c_smbus_read_word_data(file,0);
      if(res<0)
      {
	 fprintf(stderr,"Error: Could not read the value from the i2c device\n");
	 errorCount++;
      }else
      {
	 successfullCount++;
      }
      
      temp=swap_bytes(temp);
      temp=temp >> 3;
      
      printf("Succes: %i, Errorcount: %i, Temp: %f\n",successfullCount,errorCount,(float)(temp*0.0625));
      sleep(1);
   }
   
   printf("\nCalculate temp\n");
  
   close(file);
   exit(0);

  ERROR0:
   close(file);
   exit(1);
}