优秀代码摘录

int board_init (void)
{
 S3C24X0_CLOCK_POWER * const clk_power = S3C24X0_GetBase_CLOCK_POWER();//classic
 S3C24X0_GPIO * const gpio = S3C24X0_GetBase_GPIO();

 /* to reduce PLL lock time, adjust the LOCKTIME register */
 clk_power->LOCKTIME = 0xFFFFFF;

 /* configure MPLL */
 clk_power->MPLLCON = ((M_MDIV << 12) + (M_PDIV << 4) + M_SDIV);

 /* some delay between MPLL and UPLL */
 delay (4000);

 /* configure UPLL */
 clk_power->UPLLCON = ((U_M_MDIV << 12) + (U_M_PDIV << 4) + U_M_SDIV);

 /* some delay between MPLL and UPLL */
 delay (8000);

 /* set up the I/O ports */
 gpio->GPACON = 0x007FFFFF;
 gpio->GPBCON = 0x00044555;
 gpio->GPBUP = 0x000007FF;
 gpio->GPCCON = 0xAAAAAAAA;
 gpio->GPCUP = 0x0000FFFF;
 gpio->GPDCON = 0xAAAAAAAA;
 gpio->GPDUP = 0x0000FFFF;
 gpio->GPECON = 0xAAAAAAAA;
 gpio->GPEUP = 0x0000FFFF;
 gpio->GPFCON = 0x000055AA;
 gpio->GPFUP = 0x000000FF;
 gpio->GPGCON = 0xFF95FFBA;
 gpio->GPGUP = 0x0000FFFF;
 gpio->GPHCON = 0x002AFAAA;
 gpio->GPHUP = 0x000007FF;

 /* arch number of SMDK2410-Board */
 gd->bd->bi_arch_number = MACH_TYPE_SMDK2410;

 /* adress of boot parameters */
 gd->bd->bi_boot_params = 0x30000100;

 icache_enable();
 dcache_enable();

 return 0;
}

S3C24X0_CLOCK_POWER 的定义  该结构体空间与2440时钟配置寄存器对应，上面红字语句将寄存器的起始地址给了新定义的结构体变量 clk_power ，从而对结构体的操作就实现了对寄存器的操作。这是我新接触的一种思想 记录下来

typedef struct {
 S3C24X0_REG32 LOCKTIME;
 S3C24X0_REG32 MPLLCON;
 S3C24X0_REG32 UPLLCON;
 S3C24X0_REG32 CLKCON;
 S3C24X0_REG32 CLKSLOW;
 S3C24X0_REG32 CLKDIVN;
 /*modified by liukun , for 2440*/
#if defined (CONFIG_S3C2440)
 S3C24X0_REG32 CAMDIVN;
#endif
/*modified by liukun , for 2440*/
} /*__attribute__((__packed__))*/ S3C24X0_CLOCK_POWER;

static inline S3C24X0_CLOCK_POWER * S3C24X0_GetBase_CLOCK_POWER(void)
{
 return (S3C24X0_CLOCK_POWER * const)S3C24X0_CLOCK_POWER_BASE;
}