NVIDIA Legacy Interrupt Controller
All Tegra SoCs contain a legacy interrupt controller that routes
interrupts to the GIC, and also serves as a wakeup source. It is also
referred to as “ictlr”, hence the name of the binding.
The HW block exposes a number of interrupt controllers, each
implementing a set of 32 interrupts.
Required properties:
- compatible : should be: “nvidia,tegra
-ictlr”. The LIC on
subsequent SoCs remained backwards-compatible with Tegra30, so on
Tegra generations later than Tegra30 the compatible value should
include “nvidia,tegra30-ictlr”. - reg : Specifies base physical address and size of the registers.
Each controller must be described separately (Tegra20 has 4 of them,
whereas Tegra30 and later have 5). - interrupt-controller : Identifies the node as an interrupt controller.
- #interrupt-cells : Specifies the number of cells needed to encode an
interrupt source. The value must be 3. - interrupt-parent : a phandle to the GIC these interrupts are routed
to.
Notes:
- Because this HW ultimately routes interrupts to the GIC, the
interrupt specifier must be that of the GIC. - Only SPIs can use the ictlr as an interrupt parent. SGIs and PPIs
are explicitly forbidden.
Example:
ictlr: interrupt-controller@60004000 {
compatible = "nvidia,tegra20-ictlr", "nvidia,tegra-ictlr";
reg = <0x60004000 64>,
<0x60004100 64>,
<0x60004200 64>,
<0x60004300 64>;
interrupt-controller;
#interrupt-cells = <3>;
interrupt-parent = <&intc>;
};