readl writel 读写定时器 EPIT寄存器无返回，死机

四舍五入

static int MyTimerInit(void)
{
    int rtv;
    struct resource* ptimer_src;
    uint32_t reg_val;
    uint32_t cr_reg_val = 0;
    uint32_t array[3];
    printk("key-timer addr = %x \r\n",keybeep_st.ptimernode);
    rtv = of_property_read_u32_array(keybeep_st.ptimernode,"reg",array,2);
    if(rtv == 0)
    {
            printk("ptimernode reg %x %x \r\n", array[0], array[1]);
    }
    ptimer_src = request_mem_region(array[0],4*5,"BeepTimer");
    if(ptimer_src == NULL)
    {
        printk("epit1 is busy\r\n");
        return -EINVAL;
    }
    EPIT_CR = ioremap(array[0],4);
    EPIT_SR = ioremap(array[0]+4,4);
    EPIT_LR = ioremap(array[0]+8,4);
    EPIT_CMPR = ioremap(array[0]+12,4);
    EPIT_CNR = ioremap(array[0]+16,4);
    printk("1 epit1.CR = %x  \r\n",epit1.CR);
    cr_reg_val = (1<<24) | (65<<4) | ( 1 <<3 ) | (1<<2) | (1<<1);
    writel(cr_reg_val,epit1.CR);
    printk("2\r\n");
    writel(1000000,epit1.LR);
    printk("3\r\n");
    writel(0,epit1.CMPR);
    printk("4\r\n");
    //获取中断号
    keybeep_st.timerirq_num = irq_of_parse_and_map(keybeep_st.ptimernode,0);
    printk("5\r\n");
    if(keybeep_st.timerirq_num > 0)
    {
        rtv = request_irq(keybeep_st.timerirq_num,handle_Timer1Irq,IRQF_TRIGGER_NONE,"EPIT1",&keybeep_st);
        printk("timer1:  irqnum=%d\r\n",keybeep_st.timerirq_num);
    }
    else
    {
        return -EINVAL;
    }
    cr_reg_val = readl(EPIT_CR);
    printk("epit1.CR %x \r\n",cr_reg_val);
    cr_reg_val |= 1;
    writel(cr_reg_val,epit1.CR);
    return 0;
}
可以确定array[0] = 0x20D4000 或是 0x20D0000均会出现死机。

正点原子

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tianyi105224

问题解决了么。我这EPIT选择IPG，为什么的时钟频率一直是24MHz？