[PATCH] Documentation: dt: Add binding for /secure-chosen/stdout-path
From: Jerome Forissier <hidden>
Date: 2017-03-03 09:24:33
Also in:
linux-arm-kernel
Subsystem:
open firmware and flattened device tree bindings, the rest · Maintainers:
Rob Herring, Krzysztof Kozlowski, Conor Dooley, Linus Torvalds
Some platforms may use a single device tree to describe two address
spaces, as described in d9f43babb998 ("Documentation: dt: Add bindings
for Secure-only devices"). For these platforms it makes sense to define
a secure counterpart of /chosen, namely: /secure-chosen. This new node
is meant to be used by the secure firmware to pass data to the secure
OS. Only the stdout-path property is supported for now.
Signed-off-by: Jerome Forissier <redacted>
---
Documentation/devicetree/bindings/arm/secure.txt | 19 ++++++++++++++++++-
1 file changed, 18 insertions(+), 1 deletion(-)
v2
- Clarify the expected behavior when /secure-chosen/stdout-path is not
present (either the property or the node itself), as proposed by Peter
and Robin. Note that I have made the fallback to /chosen optional.
diff --git a/Documentation/devicetree/bindings/arm/secure.txt b/Documentation/devicetree/bindings/arm/secure.txt
index e31303f..c4a818e 100644
--- a/Documentation/devicetree/bindings/arm/secure.txt
+++ b/Documentation/devicetree/bindings/arm/secure.txt@@ -32,7 +32,8 @@ describe the view of Secure world using the standard bindings. These secure- bindings only need to be used where both the Secure and Normal world views need to be described in a single device tree. -Valid Secure world properties: +Valid Secure world properties +----------------------------- - secure-status : specifies whether the device is present and usable in the secure world. The combination of this with "status" allows
@@ -51,3 +52,19 @@ Valid Secure world properties: status = "disabled"; secure-status = "okay"; /* S-only */ status = "disabled"; /* disabled in both */ status = "disabled"; secure-status = "disabled"; /* disabled in both */ + +The secure-chosen node +---------------------- + +Similar to the /chosen node which serves as a place for passing data +between firmware and the operating system, the /secure-chosen node may +be used to pass data to the Secure OS. Only the properties defined +below may appear in the /secure-chosen node. + +- stdout-path : specifies the device to be used by the Secure OS for + its console output. The syntax is the same as for /chosen/stdout-path. + If the /secure-chosen node exists but the stdout-path property is not + present, the Secure OS should not perform any console output. If + /secure-chosen does not exist, the Secure OS may use the value of + /chosen/stdout-path instead (that is, use the same device as the + Normal world OS).
--
2.7.4