u-boot-2014.10移植第5天----LED、button和beep裸机程序

标签：u-boot   移植   c语言   asm   2014.10   

今天写了一个简单的key按键驱动LED和beep蜂鸣器的程序，源码如下：

/*
 * Copyright 2014(C) fulinux <fulinux@sina.com>
 */

#define GPFCON   (*(unsigned long volatile *)0x56000050)
#define GPFDAT   (*(unsigned long volatile *)0x56000054)
#define GPFUP    (*(unsigned long volatile *)0x56000058)

#define GPBCON   (*(unsigned long volatile *)0x56000010)
#define GPBDAT   (*(unsigned long volatile *)0x56000014)
#define GPBUP    (*(unsigned long volatile *)0x56000018)

#define LED0     5    /*LED0 use GPB5*/
#define LED1     6    /*LED1 use GPB6*/
#define LED2     7    /*LED2 use GPB7*/
#define LED3     8    /*LED3 use GPB8*/

#define BEEP         0    /*Buzzer us GPB0 */
#define DELAY_TIME   40000000

static inline void delay (unsigned long loops)
{
    __asm__ volatile ("1:\n"
        "subs %0, %1, #1\n"
        "bne 1b":"=r" (loops):"0" (loops));
}

void key_init(void)
{
    /* Set GPF0,GPF1,GPF2,GPF4 as GPIO input mode(00) */
    GPFCON &= ~0x33F;
    /* Enable pullup resister */
    GPFUP &= ~0x17;
    /* Set GPF0,GPF1,GPF2,GPF4 as high level */
    GPFDAT |= 0x17;
}

void led_init(void)
{
    /*  Set GPB5,GPB6,GPB7,GPB8 as GPIO output mode(01) */ 
    GPBCON = (GPBCON & ~0x3FC00) | 0x15400;
    GPBUP &= ~0x01E0;
    /* Set GPB5,GPB6,GPB7,GPB8 as high level, to turn LED0,LED1,LED2,LED3 off */
    GPBDAT |= 0x01E0;
}

void beep_init(void)
{
    GPBCON = (GPBCON|0x3)&0x1; /* Set GPB0 as GPIO output mode(0x01) */
    GPBUP &= ~1;               /* Enable pullup resister */
}

void led_off(void)
{
    /* Set GPB5,GPB6,GPB7,GPB8 as high level, to turn LED0,LED1,LED2,LED3 off */
    GPBDAT |= 0x01E0;
    delay(DELAY_TIME);
}

int main(void)
{
    beep_init();
    key_init();
    led_init();
    led_off();
    while(1)
    {
        GPBDAT &= ~(1<<BEEP);  /*  Set Beep GPIO as low level */
        while((GPFDAT & 0x17) == 0x17){
            delay(DELAY_TIME);
        }

        GPBDAT ^= (0x0F<<LED0);

        GPBDAT &= ~(1<<BEEP);  /*  Set Beep GPIO as low level */
        delay(DELAY_TIME);

        GPBDAT |= 1<<BEEP;     /*  Set Beep GPIO as high level */
        delay(DELAY_TIME);
    }
}

u-boot-2014.10移植第5天----LED、button和beep裸机程序

标签：u-boot   移植   c语言   asm   2014.10   

原文地址：http://blog.csdn.net/fulinus/article/details/40455883