gpio_test.c.txt

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//以下是gpio_test.c文件,在RedHat9上编译通过,在405EP的taihu开发板运行通过,点亮LED. 
#include   <stdio.h> 
#include   <fcntl.h> 
#include   <stdlib.h> 
#include   <unistd.h> 
#include   <sys/mman.h> 
#include   <unistd.h> 

void     *mapDirectIoRegister(unsigned   long   addr,   size_t   length); 
int         iounmap(volatile   void   *start,   size_t   length); 
void       sysLedSet(unsigned   char   value); 

#define   MAP_SIZE                                                 4096UL 
#define   MAP_MASK                                                 (MAP_SIZE   -   1) //4095 
#define   HCU3_LED_REGISTER                               0xEF600700 

volatile   unsigned   long   *ledRegister; 
#define   __PPC4xx__ 
#ifdef   __PPC4xx__ 
inline   void   out_32(volatile   unsigned   long   *addr,   unsigned   val) 
{ 
                __asm__   __volatile__( "stw%U0%X0   %1,%0;   eieio "   :   "=m "   (*addr)   :   "r "   
(val)); 
} 
/*   etc.,   cf   asm/io.h   */ 
#else 
extern   inline   void   out_32(volatile   unsigned   long   *addr,   unsigned   val) 
{   *   which   shows   you   how   to   use   PPC   assembler   code   to   ensure   correct   IO   
ordering. 

                *addr   =   val   &   0xff; 
} 
#endif 

void     *mapDirectIoRegister(unsigned   long   addr,   size_t   length) 
{ 
void   *map_base,   *   virtAddr; 
off_t   target   =   ((unsigned   int)   addr)   &   ~MAP_MASK; //off_t就是int类型;   MAP_MASK=4095UL=>   ~MAP_MASK=0xFFFFF000UL 
int   fd; 
                
if   ((fd   =   open( "/dev/mem ",   O_RDWR   |   O_SYNC))   ==   -1) //打开内存文件(驱动) 
{ 
printf( "/dev/mem   could   not   be   opened.\n "); 
exit(1); 
} 
                
//   Map   one   page 
map_base   =   mmap((void   *)target,   length,   PROT_READ   |   PROT_WRITE,   MAP_SHARED,fd,   target); 
if(map_base   ==   (void   *)   -1) 
{ 
printf( "Memory   map   failed   for   address   0x%lx\n ",   addr); 
return   map_base; 
} 
                
virtAddr   =   (void   *)   ((unsigned   long)map_base   +   (   (unsigned   long)addr   &   MAP_MASK)); //基地址+偏移量 
printf( "Memory   map   0x%lx   ->   %p   offset   0x%lx   virtual   %p\n ",   addr,   map_base,addr   &   MAP_MASK,   virtAddr); 
//输出:Memory   map   0xef600700   ->   0x30001000   offset   0x700   virtual   0x30001700 
return   virtAddr; 
} 

int   iounmap(volatile   void   *start,   size_t   length) 
{ 
unsigned   long   ofs_addr; 
ofs_addr   =   (unsigned   long)start   &   (getpagesize()-1); 
                
  /*   do   some   cleanup   when   you 're   done   with   it   */ 
return   munmap((void*)start-ofs_addr,   length+ofs_addr); 
} 

void   sysLedSet(unsigned   char   value) 
{ 
/*   For   obscure   HW   reasons,   we   have   to   negated   it   and   shift   the   value   23   bits   to   the   left     */ 
*ledRegister   =   ((   unsigned   long   )   ~value   < <23)   ; 
out_32(ledRegister,   (   unsigned   long   )   ~value   < <23   ); 
} 

int   main   (int   argc,   char   *argv[]) 
{ 
unsigned   char   j; 
printf( "%s:   %s   %s\n ",   __FUNCTION__,   __DATE__,   __TIME__   ); //输出main:   Feb     9   2007   18:13:55   
                
/*   HW   initialisation   */ 
ledRegister   =   (unsigned   long   *)mapDirectIoRegister(HCU3_LED_REGISTER,   MAP_SIZE); //MAP_SIZE=4096UL 
//上面一行输出:Memory   map   0xef600700   ->   0x30001000   offset   0x700   virtual   0x30001700 
/*   next   we   set   the   correct   control   mask   in   the   GPIO_TCR   */ 

//ledRegister[1]     =   0x7ffe0000;   /*   Three   State   Control   */ 
    
/*   Now   scroll   our   leds   and   pause   a   little   bit   between   */ 
/*for   (j=0;   j   <   8;   j++) 
{ 
sleep(1); 
printf( ". "); 
fflush(stdout); 
sysLedSet(1   < <   j); 
}*/ 

*ledRegister     =     0x7fffffff; 
//out_32(ledRegister,   0x7fffffff   ); 

sleep(1); 

*ledRegister     =   0x0; 
//out_32(ledRegister,   0x0   ); 

iounmap((volatile   void   *)HCU3_LED_REGISTER,   MAP_SIZE); 
printf( "\n%s:done\n ",   __FUNCTION__); //输出:main:done 
return   0; 
}