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author | James Hogan <james.hogan@imgtec.com> | 2012-10-09 10:54:47 +0100 |
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committer | James Hogan <james.hogan@imgtec.com> | 2013-03-02 20:09:48 +0000 |
commit | 5698c50d9da4ab2f57d98c64ea97675dcaf2a608 (patch) | |
tree | 5b82a24daa8bbb85703489340cbfdcb00a2f20a4 /Documentation/devicetree | |
parent | 63047ea36070d11f902ab7d09a5a18aea037c0f7 (diff) | |
download | linux-5698c50d9da4ab2f57d98c64ea97675dcaf2a608.tar.bz2 |
metag: Internal and external irqchips
Meta core internal interrupts (from HWSTATMETA and friends) are vectored
onto the TR1 core trigger for the current thread. This is demultiplexed
in irq-metag.c to individual Linux IRQs for each internal interrupt.
External SoC interrupts (from HWSTATEXT and friends) are vectored onto
the TR2 core trigger for the current thread. This is demultiplexed in
irq-metag-ext.c to individual Linux IRQs for each external SoC interrupt.
The external irqchip has devicetree bindings for configuring the number
of irq banks and the type of masking available.
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Grant Likely <grant.likely@secretlab.ca>
Cc: Rob Herring <rob.herring@calxeda.com>
Cc: Rob Landley <rob@landley.net>
Cc: Dom Cobley <popcornmix@gmail.com>
Cc: Simon Arlott <simon@fire.lp0.eu>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Maxime Ripard <maxime.ripard@free-electrons.com>
Cc: devicetree-discuss@lists.ozlabs.org
Cc: linux-doc@vger.kernel.org
Diffstat (limited to 'Documentation/devicetree')
-rw-r--r-- | Documentation/devicetree/bindings/metag/meta-intc.txt | 82 |
1 files changed, 82 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/metag/meta-intc.txt b/Documentation/devicetree/bindings/metag/meta-intc.txt new file mode 100644 index 000000000000..8c47dcbfabc6 --- /dev/null +++ b/Documentation/devicetree/bindings/metag/meta-intc.txt @@ -0,0 +1,82 @@ +* Meta External Trigger Controller Binding + +This binding specifies what properties must be available in the device tree +representation of a Meta external trigger controller. + +Required properties: + + - compatible: Specifies the compatibility list for the interrupt controller. + The type shall be <string> and the value shall include "img,meta-intc". + + - num-banks: Specifies the number of interrupt banks (each of which can + handle 32 interrupt sources). + + - interrupt-controller: The presence of this property identifies the node + as an interupt 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. + + - #address-cells: Specifies the number of cells needed to encode an + address. The type shall be <u32> and the value shall be 0. As such, + 'interrupt-map' nodes do not have to specify a parent unit address. + +Optional properties: + + - no-mask: The controller doesn't have any mask registers. + +* Interrupt Specifier Definition + + Interrupt specifiers consists of 2 cells encoded as follows: + + - <1st-cell>: The interrupt-number that identifies the interrupt source. + + - <2nd-cell>: The Linux interrupt flags containing level-sense information, + encoded as follows: + 1 = edge triggered + 4 = level-sensitive + +* Examples + +Example 1: + + /* + * Meta external trigger block + */ + intc: intc { + // This is an interrupt controller node. + interrupt-controller; + + // No address cells so that 'interrupt-map' nodes which + // reference this interrupt controller node do not need a parent + // address specifier. + #address-cells = <0>; + + // Two cells to encode interrupt sources. + #interrupt-cells = <2>; + + // Number of interrupt banks + num-banks = <2>; + + // No HWMASKEXT is available (specify on Chorus2 and Comet ES1) + no-mask; + + // Compatible with Meta hardware trigger block. + compatible = "img,meta-intc"; + }; + +Example 2: + + /* + * An interrupt generating device that is wired to a Meta external + * trigger block. + */ + uart1: uart@0x02004c00 { + // Interrupt source '5' that is level-sensitive. + // Note that there are only two cells as specified in the + // interrupt parent's '#interrupt-cells' property. + interrupts = <5 4 /* level */>; + + // The interrupt controller that this device is wired to. + interrupt-parent = <&intc>; + }; |