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-rw-r--r-- | Documentation/devicetree/bindings/arm/firmware/sdei.txt | 42 |
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diff --git a/Documentation/devicetree/bindings/arm/firmware/sdei.txt b/Documentation/devicetree/bindings/arm/firmware/sdei.txt new file mode 100644 index 0000000..ee3f0ff --- /dev/null +++ b/Documentation/devicetree/bindings/arm/firmware/sdei.txt @@ -0,0 +1,42 @@ +* Software Delegated Exception Interface (SDEI) + +Firmware implementing the SDEI functions described in ARM document number +ARM DEN 0054A ("Software Delegated Exception Interface") can be used by +Linux to receive notification of events such as those generated by +firmware-first error handling, or from an IRQ that has been promoted to +a firmware-assisted NMI. + +The interface provides a number of API functions for registering callbacks +and enabling/disabling events. Functions are invoked by trapping to the +privilege level of the SDEI firmware (specified as part of the binding +below) and passing arguments in a manner specified by the "SMC Calling +Convention (ARM DEN 0028B): + + r0 => 32-bit Function ID / return value + {r1 - r3} => Parameters + +Note that the immediate field of the trapping instruction must be set +to #0. + +The SDEI_EVENT_REGISTER function registers a callback in the kernel +text to handle the specified event number. + +The sdei node should be a child node of '/firmware' and have required +properties: + + - compatible : should contain: + * "arm,sdei-1.0" : For implementations complying to SDEI version 1.x. + + - method : The method of calling the SDEI firmware. Permitted + values are: + * "smc" : SMC #0, with the register assignments specified in this + binding. + * "hvc" : HVC #0, with the register assignments specified in this + binding. +Example: + firmware { + sdei { + compatible = "arm,sdei-1.0"; + method = "smc"; + }; + }; |