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+Broadcom BCM7120-style Level 2 interrupt controller
+
+This interrupt controller hardware is a second level interrupt controller that
+is hooked to a parent interrupt controller: e.g: ARM GIC for ARM-based
+platforms. It can be found on BCM7xxx products starting with BCM7120.
+
+Such an interrupt controller has the following hardware design:
+
+- outputs multiple interrupts signals towards its interrupt controller parent
+
+- controls how some of the interrupts will be flowing, whether they will
+ directly output an interrupt signal towards the interrupt controller parent,
+ or if they will output an interrupt signal at this 2nd level interrupt
+ controller, in particular for UARTs
+
+- typically has one 32-bit enable word and one 32-bit status word, but on
+ some hardware may have more than one enable/status pair
+
+- no atomic set/clear operations
+
+- not all bits within the interrupt controller actually map to an interrupt
+
+The typical hardware layout for this controller is represented below:
+
+2nd level interrupt line Outputs for the parent controller (e.g: ARM GIC)
+
+0 -----[ MUX ] ------------|==========> GIC interrupt 75
+ \-----------\
+ |
+1 -----[ MUX ] --------)---|==========> GIC interrupt 76
+ \------------|
+ |
+2 -----[ MUX ] --------)---|==========> GIC interrupt 77
+ \------------|
+ |
+3 ---------------------|
+4 ---------------------|
+5 ---------------------|
+7 ---------------------|---|===========> GIC interrupt 66
+9 ---------------------|
+10 --------------------|
+11 --------------------/
+
+6 ------------------------\
+ |===========> GIC interrupt 64
+8 ------------------------/
+
+12 ........................ X
+13 ........................ X (not connected)
+..
+31 ........................ X
+
+Required properties:
+
+- compatible: should be "brcm,bcm7120-l2-intc"
+- reg: specifies the base physical address and size of the registers;
+ multiple pairs may be specified, with the first pair handling IRQ offsets
+ 0..31 and the second pair handling 32..63
+- interrupt-controller: identifies the node as an interrupt controller
+- #interrupt-cells: specifies the number of cells needed to encode an interrupt
+ source, should be 1.
+- interrupt-parent: specifies the phandle to the parent interrupt controller
+ this one is cascaded from
+- interrupts: specifies the interrupt line(s) in the interrupt-parent controller
+ node, valid values depend on the type of parent interrupt controller
+- brcm,int-map-mask: 32-bits bit mask describing how many and which interrupts
+ are wired to this 2nd level interrupt controller, and how they match their
+ respective interrupt parents. Should match exactly the number of interrupts
+ specified in the 'interrupts' property, multiplied by the number of
+ enable/status register pairs implemented by this controller. For
+ multiple parent IRQs with multiple enable/status words, this looks like:
+ <irq0_w0 irq0_w1 irq1_w0 irq1_w1 ...>
+
+Optional properties:
+
+- brcm,irq-can-wake: if present, this means the L2 controller can be used as a
+ wakeup source for system suspend/resume.
+
+- brcm,int-fwd-mask: if present, a bit mask to configure the interrupts which
+ have a mux gate, typically UARTs. Setting these bits will make their
+ respective interrupt outputs bypass this 2nd level interrupt controller
+ completely; it is completely transparent for the interrupt controller
+ parent. This should have one 32-bit word per enable/status pair.
+
+Example:
+
+irq0_intc: interrupt-controller@f0406800 {
+ compatible = "brcm,bcm7120-l2-intc";
+ interrupt-parent = <&intc>;
+ #interrupt-cells = <1>;
+ reg = <0xf0406800 0x8>;
+ interrupt-controller;
+ interrupts = <0x0 0x42 0x0>, <0x0 0x40 0x0>;
+ brcm,int-map-mask = <0xeb8>, <0x140>;
+ brcm,int-fwd-mask = <0x7>;
+};
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