在pandaboard OMAP4中,GPIO_39上每隔10ms产生一次中断.我已在Linux驱动程序代码中为此注册了处理程序,但由于未检测到中断,因此未处理该处理程序.
我确保在硬件级别(通过探测gpio引脚)确实正在生成中断.只是软件无法检测到它.
#define GPIO_NO 39
iowrite16(0x3,gpio_39_address + 2); /* Configured the pin 22 to be used as gpio. */
ret = gpio_request(GPIO_NO,"Claiming GPIO");
if(ret < 0)
{
printk(KERN_ALERT "%s: Claiming GPIO_%d Failed\n",__func__,GPIO_NO);
return -1;
}
else
{
printk(KERN_INFO "%s: Claiming GPIO_%d successful\n",GPIO_NO);
}
ret = gpio_direction_input(GPIO_NO);
if(ret < 0)
{
printk(KERN_INFO "%s: Setting GPIO direction to input Failed\n",__func__);
return -1;
}
else
{
printk(KERN_INFO "%s: Direction of GPIO_%d set to input\n",GPIO_NO);
}
GPIO_IRQ = gpio_to_irq(GPIO_NO);
if(GPIO_IRQ < 0)
{
printk(KERN_INFO "%s: Mapping GPIO_%d to IRQ Failed\n",GPIO_NO);
return -1;
}
else
{
printk(KERN_INFO "%s: Mapping GPIO_%d to IRQ_%d successful\n",GPIO_NO,GPIO_IRQ);
}
if((request_irq(GPIO_IRQ,ten_ms_int,IRQF_TRIGGER_FALLING,DEVICE_NAME,NULL)))
{
printk(KERN_ALERT "%s: requeseting GPIO_IRQ %d Failed\n",GPIO_IRQ);
return -1;
}
else
{
printk(KERN_INFO "%s: requesting GPIO_IRQ %d successful\n",GPIO_IRQ);
}
irqreturn_t ten_ms_int(int irq,void *dev_id)
{
T_UINT32 l;
/* Enable spi channel */
l = ioread32(spi_base + SPI_CHCONF0);
l |= SPI_CHCONF0_FORCE;
iowrite32(l,(spi_base + SPI_CHCONF0));
l = ioread32(spi_base + SPI_CHCTRL0);
l |= SPI_CHCTRL_EN;
iowrite32(l,(spi_base + SPI_CHCTRL0));
/* Enable dma channel 0 */
l = ioread32(sdma_base + SDMA_CCR(CHANNEL0));
l |= SDMA_CCR_ENABLE;
iowrite32(l,sdma_base + SDMA_CCR(CHANNEL0));
/* Enable dma channel 1 */
l = ioread32(sdma_base + SDMA_CCR(CHANNEL1));
l |= SDMA_CCR_ENABLE;
iowrite32(l,sdma_base + SDMA_CCR(CHANNEL1));
//printk(KERN_INFO "%s: 10ms interrupt detected %d\n",irq); /* I know that I've to remove this printk statement */
return IRQ_HANDLED;
}
GPIO_39属于存储体GPIO2,相应的中断号为32.但是,gpio_to_irq()的返回值为199.这是另一个引起关注的原因.
最佳答案
明确地使GPIO引脚检测下降沿.
原文链接:https://www.f2er.com/linux/440949.html在gpio模块级别,必须启用gpio的FALLING_DETECT.