// Arlotto 2008 UNIVERSITY OF TOULON IUT GEII www : arlotto.univ-tln.fr
// Olimex EP930X Handling GPIO from user space
// PORTH4 : Button (pulled up)
// PORTE0  : Green Led
// PORTE1  : Red Led
// Compile options : arm-linux-gcc -Wall -mcpu=arm9   
// This program unlock device config to allow port H to be used as normal GPIO (NotIDE).
// Then waits until button is pressed ( busy waiting )
// Then loops 5 times to blink led while printing Port H and E states.
// It then restore initial register values

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

int main(int argc, char **argv)
{
   volatile unsigned int *PEDR, *PEDDR, *PHDR, *PHDDR;
   volatile unsigned int *DeviceCfg, *SysSWLock ;
   unsigned int oldPEDR,oldPEDDR,oldPHDR,oldPHDDR,oldDeviceCfg;
   int i;

   unsigned int state;

   unsigned char *start;

   unsigned char *CfgBase ;

   int fd = open("/dev/mem", O_RDWR|O_SYNC);

   start   = mmap(0, getpagesize(), PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0x80840000);
   CfgBase = mmap(0, getpagesize(), PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0x80930000);
   
   DeviceCfg = (unsigned int *)(CfgBase + 0x80);  
   SysSWLock = (unsigned int *)(CfgBase + 0xC0);  

   PHDR = (unsigned int *)(start + 0x40);     // port h
   PHDDR = (unsigned int *)(start + 0x44);    // port h direction register
   PEDR = (unsigned int *)(start + 0x20);     // port e data
   PEDDR = (unsigned int *)(start + 0x24);    // port e direction register
  
   oldPEDR = *PEDR ;
   oldPEDDR = *PEDDR ;
   oldPHDR = *PHDR ;
   oldPHDDR = *PHDDR ;
   oldDeviceCfg = *DeviceCfg ;

   //printf("sizeof int :%d sizeof char : %d\n",sizeof(int),sizeof(char));
   printf("Etat initial :\n");
   printf("PEDR : %x PEDDR : %x : PHDR : %x PHDDR : %x \n",*PEDR,*PEDDR,*PHDR,*PHDDR);
   printf("DeviceCfg : %x\n",*DeviceCfg);
   
  // Unlocking SWLOCK to permit configuration of PORTH to normal GPIO port.
  if(*SysSWLock == 0x00000001 ) {
      printf("Sys is open\n");
   } else
   {
      printf("Sys is locked\n");
      printf("Try to open......");
      *SysSWLock = 0x000000AA ;     
   }
  if(*SysSWLock == 0x00000001 ) {
      printf("Now Sys is open !\n");
   } else
   {
     printf("Failed to open Sys...\n");
     close(fd);
     return 1 ;
   }

   
   *DeviceCfg = *DeviceCfg | 0x00000800 ;  // PORTH is not IDE !

    printf("New DeviceCfg : %x\n",*DeviceCfg);


   *PHDDR = *PHDDR & (~0x00000010);	      // port h b4 input
   *PEDDR |= 0x03;                             // port e b0 and b1 output
 
   printf("button demo!\n");

   state = *PHDR;                             // read initial state
   printf("PHDR=%x PHDDR=%x\n",*PHDR,*PHDDR);
   printf("PEDR=%x PEDDR=%x\n",*PEDR,*PEDDR);

   printf("Press Button to continue....");
   fflush(stdout); 
   while (state & 0x0010) {                     // wait until button goes low bit 4 
      state = *PHDR;                          // remember bit 0 is pulled up with 4.7k ohm
   }
   printf("button Pressed!!!\n");

   // blink 5 times, sleep 1 second so it's visible
   for (i = 0; i < 5; i++) {
      *PEDR = 0x01;  // Green Led On Red Led Off;
      sleep(1); 

      printf("PHDR=%x :",*PHDR);
      printf("PEDR=%x\n",*PEDR);

      *PEDR = 0x02; // Green Led Off Red Led On ;
      sleep(1);
   }

   // Restore initial register values
   // Relock seems to be done automaticaly
   *PEDR = oldPEDR ;
   *PEDDR = oldPEDDR;
   *PHDR = oldPHDR ;
   *PHDDR = oldPHDDR ;
   *DeviceCfg = oldDeviceCfg  ;
   
   close(fd);
   printf("Done...\n");
   return 0;
}