GPIO_39 上每 10ms 产生一个中断熊猫板 OMAP4 http://www.ti.com/product/OMAP4460。我已在 Linux 驱动程序代码中为此注册了一个处理程序，但由于未检测到中断，因此未调用该处理程序。
我在硬件级别（通过探测 GPIO 引脚）确保中断确实正在生成。只是软件无法检测到它。
我的驱动程序代码中有以下内容。
#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", __func__, 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", __func__, GPIO_NO);
}
GPIO_IRQ = gpio_to_irq(GPIO_NO);
if(GPIO_IRQ < 0)
{
printk(KERN_INFO "%s: Mapping GPIO_%d to IRQ failed\n", __func__, GPIO_NO);
return -1;
}
else
{
printk(KERN_INFO "%s: Mapping GPIO_%d to IRQ_%d successful\n", __func__, 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", __func__, GPIO_IRQ);
return -1;
}
else
{
printk(KERN_INFO "%s: requesting GPIO_IRQ %d successful\n", __func__, 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", __func__, irq); /* I know that I've to remove this printk statement */
return IRQ_HANDLED;
}
GPIO_39 属于 GPIO2 组，对应的中断号为 32。但是，返回值gpio_to_irq()是199。这是另一个令人担忧的问题。
如果代码有问题或者我遗漏了什么，请告诉我。
