Re: [PATCH v3 2/4] Documentation: bindings: mfd: cros ec: document vbc EC property

From: Emilio LÃpez
Date: Wed Sep 23 2015 - 10:31:51 EST


Hi Lee,

On 22/09/15 21:34, Lee Jones wrote:
On Mon, 21 Sep 2015, Emilio LÃpez wrote:

Some EC implementations include a small nvram space used to store
verified boot context data. This boolean property lets us indicate
whether this space is available or not on a specific EC implementation.

Signed-off-by: Emilio LÃpez <emilio.lopez@xxxxxxxxxxxxxxx>
---

Patch is new in v3, split from 3/4

Documentation/devicetree/bindings/mfd/cros-ec.txt | 4 ++++
1 file changed, 4 insertions(+)

diff --git a/Documentation/devicetree/bindings/mfd/cros-ec.txt b/Documentation/devicetree/bindings/mfd/cros-ec.txt
index 1777916..136e0c2 100644
--- a/Documentation/devicetree/bindings/mfd/cros-ec.txt
+++ b/Documentation/devicetree/bindings/mfd/cros-ec.txt
@@ -34,6 +34,10 @@ Required properties (LPC):
- compatible: "google,cros-ec-lpc"
- reg: List of (IO address, size) pairs defining the interface uses

+Optional properties (all):
+- google,has-vbc-nvram: Some implementations of the EC include a small
+ nvram space used to store verified boot context data. This boolean flag
+ is used to specify whether this nvram is present or not.

Is there no way to check for this at runtime?

You can issue a read and see if it succeeds, but the problem is that some EC implementations return success even when they don't implement the functionality.

Cheers,

Emilio
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