Linux Device Drivers Development

GPIO mapping to IRQ in the device tree

You can easily map the GPIO to the IRQ in the device tree. Two properties are used to specify an interrupt:

• interrupt-parent: This is the GPIO controller for the GPIO
• interrupts: This is the interrupts specifier list

These apply to legacy and descriptor-based interfaces. The IRQ specifier depends on the #interrupt-cell property of the GPIO controller providing this GPIO. #interrupt-cell determines the number of cells used when specifying the interrupt. Generally, the first cell represents the GPIO number to map to an IRQ and the second cell represents level/edge should trigger the interrupt. In any case, the interrupt specifier always depends on its parent (the one that has the interrupt-controller ...