1C6X Interrupt Chips
2-------------------
3
4* C64X+ Core Interrupt Controller
5
6  The core interrupt controller provides 16 prioritized interrupts to the
7  C64X+ core. Priority 0 and 1 are used for reset and NMI respectively.
8  Priority 2 and 3 are reserved. Priority 4-15 are used for interrupt
9  sources coming from outside the core.
10
11  Required properties:
12  --------------------
13  - compatible: Should be "ti,c64x+core-pic";
14  - #interrupt-cells: <1>
15
16  Interrupt Specifier Definition
17  ------------------------------
18  Single cell specifying the core interrupt priority level (4-15) where
19  4 is highest priority and 15 is lowest priority.
20
21  Example
22  -------
23  core_pic: interrupt-controller@0 {
24	interrupt-controller;
25	#interrupt-cells = <1>;
26	compatible = "ti,c64x+core-pic";
27  };
28
29
30
31* C64x+ Megamodule Interrupt Controller
32
33  The megamodule PIC consists of four interrupt mupliplexers each of which
34  combine up to 32 interrupt inputs into a single interrupt output which
35  may be cascaded into the core interrupt controller. The megamodule PIC
36  has a total of 12 outputs cascading into the core interrupt controller.
37  One for each core interrupt priority level. In addition to the combined
38  interrupt sources, individual megamodule interrupts may be cascaded to
39  the core interrupt controller. When an individual interrupt is cascaded,
40  it is no longer handled through a megamodule interrupt combiner and is
41  considered to have the core interrupt controller as the parent.
42
43  Required properties:
44  --------------------
45  - compatible: "ti,c64x+megamod-pic"
46  - interrupt-controller
47  - #interrupt-cells: <1>
48  - reg: base address and size of register area
49  - interrupt-parent: must be core interrupt controller
50  - interrupts: This should have four cells; one for each interrupt combiner.
51                The cells contain the core priority interrupt to which the
52                corresponding combiner output is wired.
53
54  Optional properties:
55  --------------------
56  - ti,c64x+megamod-pic-mux: Array of 12 cells correspnding to the 12 core
57                             priority interrupts. The first cell corresponds to
58                             core priority 4 and the last cell corresponds to
59                             core priority 15. The value of each cell is the
60                             megamodule interrupt source which is MUXed to
61                             the core interrupt corresponding to the cell
62                             position. Allowed values are 4 - 127. Mapping for
63                             interrupts 0 - 3 (combined interrupt sources) are
64                             ignored.
65
66  Interrupt Specifier Definition
67  ------------------------------
68  Single cell specifying the megamodule interrupt source (4-127). Note that
69  interrupts mapped directly to the core with "ti,c64x+megamod-pic-mux" will
70  use the core interrupt controller as their parent and the specifier will
71  be the core priority level, not the megamodule interrupt number.
72
73  Examples
74  --------
75  megamod_pic: interrupt-controller@1800000 {
76	compatible = "ti,c64x+megamod-pic";
77	interrupt-controller;
78	#interrupt-cells = <1>;
79	reg = <0x1800000 0x1000>;
80	interrupt-parent = <&core_pic>;
81	interrupts = < 12 13 14 15 >;
82  };
83
84  This is a minimal example where all individual interrupts go through a
85  combiner. Combiner-0 is mapped to core interrupt 12, combiner-1 is mapped
86  to interrupt 13, etc.
87
88
89  megamod_pic: interrupt-controller@1800000 {
90	compatible = "ti,c64x+megamod-pic";
91	interrupt-controller;
92	#interrupt-cells = <1>;
93	reg = <0x1800000 0x1000>;
94	interrupt-parent = <&core_pic>;
95	interrupts = < 12 13 14 15 >;
96	ti,c64x+megamod-pic-mux = <  0  0  0  0
97                                    32  0  0  0
98                                     0  0  0  0 >;
99  };
100
101  This the same as the first example except that megamodule interrupt 32 is
102  mapped directly to core priority interrupt 8. The node using this interrupt
103  must set the core controller as its interrupt parent and use 8 in the
104  interrupt specifier value.
105