Add the rt linux 4.1.3-rt3 as base

[kvmfornfv.git] / kernel / Documentation / devicetree / bindings / c6x / interrupt.txt

diff --git a/kernel/Documentation/devicetree/bindings/c6x/interrupt.txt b/kernel/Documentation/devicetree/bindings/c6x/interrupt.txt
new file mode 100644 (file)
index 0000000..42bb796
--- /dev/null
+++ b/kernel/Documentation/devicetree/bindings/c6x/interrupt.txt
@@ -0,0 +1,104 @@
+C6X Interrupt Chips
+-------------------
+
+* C64X+ Core Interrupt Controller
+
+  The core interrupt controller provides 16 prioritized interrupts to the
+  C64X+ core. Priority 0 and 1 are used for reset and NMI respectively.
+  Priority 2 and 3 are reserved. Priority 4-15 are used for interrupt
+  sources coming from outside the core.
+
+  Required properties:
+  --------------------
+  - compatible: Should be "ti,c64x+core-pic";
+  - #interrupt-cells: <1>
+
+  Interrupt Specifier Definition
+  ------------------------------
+  Single cell specifying the core interrupt priority level (4-15) where
+  4 is highest priority and 15 is lowest priority.
+
+  Example
+  -------
+  core_pic: interrupt-controller@0 {
+       interrupt-controller;
+       #interrupt-cells = <1>;
+       compatible = "ti,c64x+core-pic";
+  };
+
+
+
+* C64x+ Megamodule Interrupt Controller
+
+  The megamodule PIC consists of four interrupt mupliplexers each of which
+  combine up to 32 interrupt inputs into a single interrupt output which
+  may be cascaded into the core interrupt controller. The megamodule PIC
+  has a total of 12 outputs cascading into the core interrupt controller.
+  One for each core interrupt priority level. In addition to the combined
+  interrupt sources, individual megamodule interrupts may be cascaded to
+  the core interrupt controller. When an individual interrupt is cascaded,
+  it is no longer handled through a megamodule interrupt combiner and is
+  considered to have the core interrupt controller as the parent.
+
+  Required properties:
+  --------------------
+  - compatible: "ti,c64x+megamod-pic"
+  - interrupt-controller
+  - #interrupt-cells: <1>
+  - reg: base address and size of register area
+  - interrupt-parent: must be core interrupt controller
+  - interrupts: This should have four cells; one for each interrupt combiner.
+                The cells contain the core priority interrupt to which the
+                corresponding combiner output is wired.
+
+  Optional properties:
+  --------------------
+  - ti,c64x+megamod-pic-mux: Array of 12 cells correspnding to the 12 core
+                             priority interrupts. The first cell corresponds to
+                             core priority 4 and the last cell corresponds to
+                             core priority 15. The value of each cell is the
+                             megamodule interrupt source which is MUXed to
+                             the core interrupt corresponding to the cell
+                             position. Allowed values are 4 - 127. Mapping for
+                             interrupts 0 - 3 (combined interrupt sources) are
+                             ignored.
+
+  Interrupt Specifier Definition
+  ------------------------------
+  Single cell specifying the megamodule interrupt source (4-127). Note that
+  interrupts mapped directly to the core with "ti,c64x+megamod-pic-mux" will
+  use the core interrupt controller as their parent and the specifier will
+  be the core priority level, not the megamodule interrupt number.
+
+  Examples
+  --------
+  megamod_pic: interrupt-controller@1800000 {
+       compatible = "ti,c64x+megamod-pic";
+       interrupt-controller;
+       #interrupt-cells = <1>;
+       reg = <0x1800000 0x1000>;
+       interrupt-parent = <&core_pic>;
+       interrupts = < 12 13 14 15 >;
+  };
+
+  This is a minimal example where all individual interrupts go through a
+  combiner. Combiner-0 is mapped to core interrupt 12, combiner-1 is mapped
+  to interrupt 13, etc.
+
+
+  megamod_pic: interrupt-controller@1800000 {
+       compatible = "ti,c64x+megamod-pic";
+       interrupt-controller;
+       #interrupt-cells = <1>;
+       reg = <0x1800000 0x1000>;
+       interrupt-parent = <&core_pic>;
+       interrupts = < 12 13 14 15 >;
+       ti,c64x+megamod-pic-mux = <  0  0  0  0
+                                    32  0  0  0
+                                     0  0  0  0 >;
+  };
+
+  This the same as the first example except that megamodule interrupt 32 is
+  mapped directly to core priority interrupt 8. The node using this interrupt
+  must set the core controller as its interrupt parent and use 8 in the
+  interrupt specifier value.