C-在OMAP4460上设置GPTImer1

Question

我在OMAP4460（Cortex a9）上写下裸机代码（否OS），而我无法成功地设置GPTImer1。

这是我的代码（通过遵循OMAP4460 TRM）

/* for forwarding pending interrupts from distributor to Cpu interfaces */
*(volatile unsigned int *)(GICD_BASE + GICD_CTLR ) |= 0x00000001;
/* signaling interrupt by the cpu interface to the connected processor*/
*(volatile unsigned int *)(GICC_BASE + GICC_CTLR ) |= 0x00000001;
/* position the timer1 handler */
irq_table_function[GPT1_IRQ] = timer1handler;
/* clocks timer1 block */
*(volatile unsigned int *)CM_WKUP_CLKSTCTRL |= 0x00000003;
*(volatile unsigned int *)CM_WKUP_GPTIMER1_CLKCTRL |= 0x01000000;
*(volatile unsigned int *)CM_WKUP_GPTIMER1_CLKCTRL |= 0x00000002;
/* enable GPTimer1 functional and interface blocks */
*(volatile unsigned int *)GPT1MS_TIOCP_CFG |= 0x00000300;
/* capture interrupt enable */
*(volatile unsigned int *)GPT_TIER |= 0x00000004;
/* enable autoreload */
*(volatile unsigned int *)GPT_TCLR |= 0x00000002;
/* prescaler equal to zero */
*(volatile unsigned int *)GPT_TCLR &= ~0x0000003C;
/* positive increment value */
*(volatile unsigned int *)GPT_TPIR = 232000;
/* negative increment value */
*(volatile int *)GPT_TNIR = -768000;
/* load value */
*(volatile unsigned int *)GPT_TLDR = 0xFFFFFFE0;
/* enable timer1 */
*(volatile unsigned int *)GPT_TIER |= 0x00000001;

当我运行代码时，我从不转到中断向量表，我的中断向量表已正确设置，因为" svc 0"工作。

我什至看不到计时器计数器运行。

请任何想法，关于我缺少的东西？罗尼。

Answer 1

您是否检查过计时器模块是否启动，并且对计时器模块的时钟已启用？时钟源的选择是通过电源，重置和时钟管理（PRCM）模块（TRM的第3章）进行的。

如果您没有启用电源并将时钟源配置为PRCM模块中的计时器外围块，则计时器将简单地做任何事情。

Answer 2

我终于获得了正确的初始化序列，但忘记了我的代码。

这就是我初始化gptimer1的方式，希望它能有所帮助

/* clocks timer1 block */
    *(volatile unsigned int *)CM_WKUP_CLKSTCTRL |= 0x00000003;
    *(volatile unsigned int *)CM_WKUP_GPTIMER1_CLKCTRL &= ~0x01000000;
    *(volatile unsigned int *)CM_WKUP_GPTIMER1_CLKCTRL |= 0x00000002;
   /* enables for forwarding pending interrupts from distributor
      to Cpu interfaces */
    *(volatile unsigned int *)(GICD_BASE + GICD_CTLR ) |= 0x00000003;
    /* set the priority of the interrupt */
    *(volatile unsigned int *)(GICD_BASE + GICD_IPRIORITYR_IRQ37 ) |= 0x00000200;
    /* set enable bit of IRQ37 */
    *(volatile unsigned int *)(GICD_BASE + GICD_ISENABLER37) |= 0x00000002;
    /* enables signaling interrupt by the cpu interface to the connected processor*/
    *(volatile unsigned int *)(GICC_BASE + GICC_CTLR ) |= 0x00000003;
    /* interrupt priority mask */
    *(volatile unsigned int *)(GICC_BASE + GICC_PMR ) = 0x00000080;
    /* forward the interrupt only to the processor which request the interrupt */
    *(volatile unsigned int *)(GICD_BASE + GICD_SGIR) |= 0x02000000;
    /* software reset */
    *(volatile unsigned int *)GPT1MS_TIOCP_CFG |= 0x00000002;
    /* RESET & Power settings*/
    /* wait until reset release */
    while( (*(volatile unsigned int *)GPT_TISTAT & 0x00000001) == 0)
        waitingtime++;
    /*GPT1MS_TIOCP_CFG [0]AUTOIDLE =0x0 : L4 clock free-running*/
    *(volatile unsigned int *)GPT1MS_TIOCP_CFG &= ~(0x1 << 0);
    /* idle mode equals to no-idle mode */
    *(volatile unsigned int *)GPT1MS_TIOCP_CFG |= 0x00000008;
    /*Functional clock is maintained during wake-up period */
    *(volatile unsigned int *)GPT1MS_TIOCP_CFG |= 0x00000300;
    /*NO Wake-up line assertion GPT1MS_TIOCP_CFG[2]ENAWAKEUP=0x0*/
    *(volatile unsigned int *)GPT1MS_TIOCP_CFG &= ~(0x1 << 2) ;
    /*GPT1MS_TIOCP_CFG [5]EMUFREE =0x1 : Timer counter free running in emulation*/
    *(volatile unsigned int *)GPT1MS_TIOCP_CFG |= (0x1 << 5);
    /* Enable wake-up interrupt events */
    *(volatile unsigned int *)GPT_TWER |= 0x00000007;
    /* Posted mode active */
    *(volatile unsigned int *)GPT_TSICR |= 0x00000004;
    /* enable autoreload */
    *(volatile unsigned int *)GPT_TCLR |= 0x00000002;
    /* set prescale clock timer value (PTV) to 1 */
    /* set PREscaler =128
and thus FCLK=38.4 MHz / 128 = 300 KHz << OCPCLK=38.4 / 4 = 9.6 MHz */
    *(volatile unsigned int *)GPT_TCLR |= 0x00000018;
    /* enable prescaler */
    *(volatile unsigned int *)GPT_TCLR |= 0x00000020;
    /* Overflow interrupt enable */
    *(volatile unsigned int *)GPT_TIER |= 0x00000007;
    /* Load timer counter value */
    *(volatile unsigned int *)GPT_TCRR = 0xFD000000;
    /* load value */
    *(volatile unsigned int *)GPT_TLDR = 0xFFE00000;

    *(volatile unsigned int *)GPT_TPIR = 232000;
    /* negative increment value */
    *(volatile int *)GPT_TNIR = 0xFFF44800;
    /* we position the timer1 handler */
     irq_table_function[GPT1_IRQ] = timer1handler;
    /* enable timer1 */
    *(volatile unsigned int *)GPT_TCLR |= 0x00000001;

最好的问候

罗尼