1Marvell ICU Interrupt Controller
2--------------------------------
3
4The Marvell ICU (Interrupt Consolidation Unit) controller is
5responsible for collecting all wired-interrupt sources in the CP and
6communicating them to the GIC in the AP, the unit translates interrupt
7requests on input wires to MSG memory mapped transactions to the GIC.
8These messages will access a different GIC memory area depending on
9their type (NSR, SR, SEI, REI, etc).
10
11Required properties:
12
13- compatible: Should be "marvell,cp110-icu"
14
15- reg: Should contain ICU registers location and length.
16
17Subnodes: Each group of interrupt is declared as a subnode of the ICU,
18with their own compatible.
19
20Required properties for the icu_nsr/icu_sei subnodes:
21
22- compatible: Should be one of:
23              * "marvell,cp110-icu-nsr"
24	      * "marvell,cp110-icu-sr"
25	      * "marvell,cp110-icu-sei"
26	      * "marvell,cp110-icu-rei"
27
28- #interrupt-cells: Specifies the number of cells needed to encode an
29  interrupt source. The value shall be 2.
30
31  The 1st cell is the index of the interrupt in the ICU unit.
32
33  The 2nd cell is the type of the interrupt. See arm,gic.txt for
34  details.
35
36- interrupt-controller: Identifies the node as an interrupt
37  controller.
38
39- msi-parent: Should point to the GICP controller, the GIC extension
40  that allows to trigger interrupts using MSG memory mapped
41  transactions.
42
43Note: each 'interrupts' property referring to any 'icu_xxx' node shall
44      have a different number within [0:206].
45
46Example:
47
48icu: interrupt-controller@1e0000 {
49	compatible = "marvell,cp110-icu";
50	reg = <0x1e0000 0x440>;
51
52	CP110_LABEL(icu_nsr): interrupt-controller@10 {
53		compatible = "marvell,cp110-icu-nsr";
54		reg = <0x10 0x20>;
55		#interrupt-cells = <2>;
56		interrupt-controller;
57		msi-parent = <&gicp>;
58	};
59
60	CP110_LABEL(icu_sei): interrupt-controller@50 {
61		compatible = "marvell,cp110-icu-sei";
62		reg = <0x50 0x10>;
63		#interrupt-cells = <2>;
64		interrupt-controller;
65		msi-parent = <&sei>;
66	};
67};
68
69node1 {
70	interrupt-parent = <&icu_nsr>;
71	interrupts = <106 IRQ_TYPE_LEVEL_HIGH>;
72};
73
74node2 {
75	interrupt-parent = <&icu_sei>;
76	interrupts = <107 IRQ_TYPE_LEVEL_HIGH>;
77};
78
79/* Would not work with the above nodes */
80node3 {
81	interrupt-parent = <&icu_nsr>;
82	interrupts = <107 IRQ_TYPE_LEVEL_HIGH>;
83};
84
85The legacy bindings were different in this way:
86
87- #interrupt-cells: The value was 3.
88	The 1st cell was the group type of the ICU interrupt. Possible
89	group types were:
90	ICU_GRP_NSR (0x0) : Shared peripheral interrupt, non-secure
91	ICU_GRP_SR  (0x1) : Shared peripheral interrupt, secure
92	ICU_GRP_SEI (0x4) : System error interrupt
93	ICU_GRP_REI (0x5) : RAM error interrupt
94	The 2nd cell was the index of the interrupt in the ICU unit.
95	The 3rd cell was the type of the interrupt. See arm,gic.txt for
96	details.
97
98Example:
99
100icu: interrupt-controller@1e0000 {
101	compatible = "marvell,cp110-icu";
102	reg = <0x1e0000 0x440>;
103
104	#interrupt-cells = <3>;
105	interrupt-controller;
106	msi-parent = <&gicp>;
107};
108
109node1 {
110	interrupt-parent = <&icu>;
111	interrupts = <ICU_GRP_NSR 106 IRQ_TYPE_LEVEL_HIGH>;
112};
113