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-rw-r--r-- | Documentation/devicetree/bindings/metag/pdc-intc.txt | 105 |
1 files changed, 105 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/metag/pdc-intc.txt b/Documentation/devicetree/bindings/metag/pdc-intc.txt new file mode 100644 index 00000000000..a6911855034 --- /dev/null +++ b/Documentation/devicetree/bindings/metag/pdc-intc.txt @@ -0,0 +1,105 @@ +* ImgTec Powerdown Controller (PDC) Interrupt Controller Binding + +This binding specifies what properties must be available in the device tree +representation of a PDC IRQ controller. This has a number of input interrupt +lines which can wake the system, and are passed on through output interrupt +lines. + +Required properties: + + - compatible: Specifies the compatibility list for the interrupt controller. + The type shall be <string> and the value shall include "img,pdc-intc". + + - reg: Specifies the base PDC physical address(s) and size(s) of the + addressable register space. The type shall be <prop-encoded-array>. + + - interrupt-controller: The presence of this property identifies the node + as an interrupt controller. No property value shall be defined. + + - #interrupt-cells: Specifies the number of cells needed to encode an + interrupt source. The type shall be a <u32> and the value shall be 2. + + - num-perips: Number of waking peripherals. + + - num-syswakes: Number of SysWake inputs. + + - interrupts: List of interrupt specifiers. The first specifier shall be the + shared SysWake interrupt, and remaining specifies shall be PDC peripheral + interrupts in order. + +* Interrupt Specifier Definition + + Interrupt specifiers consists of 2 cells encoded as follows: + + - <1st-cell>: The interrupt-number that identifies the interrupt source. + 0-7: Peripheral interrupts + 8-15: SysWake interrupts + + - <2nd-cell>: The level-sense information, encoded using the Linux interrupt + flags as follows (only 4 valid for peripheral interrupts): + 0 = none (decided by software) + 1 = low-to-high edge triggered + 2 = high-to-low edge triggered + 3 = both edge triggered + 4 = active-high level-sensitive (required for perip irqs) + 8 = active-low level-sensitive + +* Examples + +Example 1: + + /* + * TZ1090 PDC block + */ + pdc: pdc@0x02006000 { + // This is an interrupt controller node. + interrupt-controller; + + // Three cells to encode interrupt sources. + #interrupt-cells = <2>; + + // Offset address of 0x02006000 and size of 0x1000. + reg = <0x02006000 0x1000>; + + // Compatible with Meta hardware trigger block. + compatible = "img,pdc-intc"; + + // Three peripherals are connected. + num-perips = <3>; + + // Four SysWakes are connected. + num-syswakes = <4>; + + interrupts = <18 4 /* level */>, /* Syswakes */ + <30 4 /* level */>, /* Peripheral 0 (RTC) */ + <29 4 /* level */>, /* Peripheral 1 (IR) */ + <31 4 /* level */>; /* Peripheral 2 (WDT) */ + }; + +Example 2: + + /* + * An SoC peripheral that is wired through the PDC. + */ + rtc0 { + // The interrupt controller that this device is wired to. + interrupt-parent = <&pdc>; + + // Interrupt source Peripheral 0 + interrupts = <0 /* Peripheral 0 (RTC) */ + 4> /* IRQ_TYPE_LEVEL_HIGH */ + }; + +Example 3: + + /* + * An interrupt generating device that is wired to a SysWake pin. + */ + touchscreen0 { + // The interrupt controller that this device is wired to. + interrupt-parent = <&pdc>; + + // Interrupt source SysWake 0 that is active-low level-sensitive + interrupts = <8 /* SysWake0 */ + 8 /* IRQ_TYPE_LEVEL_LOW */>; + }; |