[PATCH 06/11] dt-bindings: add devicetree binding for describing arm64 SDEI firmware

[James Morse]

The Software Delegated Exception Interface (SDEI) is an ARM standard
for registering callbacks from the platform firmware into the OS.
This is typically used to implement RAS notifications.

Add a new devicetree binding to describe the SDE firmware interface.

Signed-off-by: James Morse <james.morse at arm.com>
---
 Documentation/devicetree/bindings/arm/sdei.txt | 37 ++++++++++++++++++++++++++
 1 file changed, 37 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/arm/sdei.txt

diff --git a/Documentation/devicetree/bindings/arm/sdei.txt b/Documentation/devicetree/bindings/arm/sdei.txt
new file mode 100644
index 000000000000..69220d995286
--- /dev/null
+++ b/Documentation/devicetree/bindings/arm/sdei.txt
@@ -0,0 +1,37 @@
+* 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.
+
+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 similar to that specified by AAPCS:
+
+	 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.
+
+Main node 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:
+	sdei {
+		compatible	= "arm,sdei-1.0";
+		method		= "smc";
+	};
-- 
2.10.1