PROCESSOR-SDK-AM64X: GPIO Interrupt

Such as,

interrupt-parent = <&main_gpio1>;
interrupts = <75 IRQ_TYPE_LEVEL_LOW>;

Does it mean use GPIO1_75 as interrupt input, and low level trigger? 

How does the kernel source code bind an irq handler function using the gpio information in DTS?

xixiguohx said:

interrupt-parent = <&main_gpio1>;
interrupts = <75 IRQ_TYPE_LEVEL_LOW>;

Does it mean use GPIO1_75 as interrupt input, and low level trigger? 

Yes.

xixiguohx said:

How does the kernel source code bind an irq handler function using the gpio information in DTS?

In a quick search in kernel source, I didn't find a simple driver as the example of such GPIO interrupt usage. I will look into it further next week to see if I can find one in kernel code.

Hi Bin，

Thanks for your reply! If there's any update, please share to me.

I tried modify dts like above, and I used

request_irq(spimydev->spi->irq, spi_mydev_interrupt,IRQF_TRIGGER_LOW, "spimydev", NULL);

in kernel code.

And I got error below,

genirq: Setting trigger mode 8 for irq 528 failed (gpio_irq_type+0x0/0x18)

Best Regards

xxg

xixiguohx said:

interrupt-parent = <&main_gpio1>;
interrupts = <75 IRQ_TYPE_LEVEL_LOW>;

In the same DT node which specifies this GPIO interrupt, did you add the reference to the pinmux setting for gpio1_75? I am not sure if this would be related to gpio interrupt, but referring to the pinmux setting here is needed to activate the pinmux configuration.

I added the pinmux configuration,

AM64X_IOPAD(0x028C, PIN_INPUT | PULL_DISABLE | INPUT_EN | (1<<21), 7)    /*GPIO1_75 */

And also added this pinmux configuration to the device definition node.

I found that request_irq with IRQF_TRIGGER_FALLING, it can request_irq success. But I don't know why request_irq with IRQF_TRIGGER_LOW  can not work.

Best Regards

xxg

Hi,

xixiguohx said:

I found that request_irq with IRQF_TRIGGER_FALLING, it can request_irq success. But I don't know why request_irq with IRQF_TRIGGER_LOW  can not work.

The AM64x TRM section 12.1.2.1.1 "GPIO Features" states "Interrupt can be triggered by rising and/or falling edge", so it seem level interrupt is not supported on GPIO modules.

Hi Bin,

Thank you,  I will check this later.

Best Regards

xxg