From mboxrd@z Thu Jan 1 00:00:00 1970 From: emilio.lopez@collabora.co.uk (=?UTF-8?Q?Emilio_L=c3=b3pez?=) Date: Wed, 23 Sep 2015 11:31:22 -0300 Subject: [PATCH v3 2/4] Documentation: bindings: mfd: cros ec: document vbc EC property In-Reply-To: <20150923003401.GB16510@x1> References: <1442842703-5309-1-git-send-email-emilio.lopez@collabora.co.uk> <1442842703-5309-3-git-send-email-emilio.lopez@collabora.co.uk> <20150923003401.GB16510@x1> Message-ID: <5602B7BA.8020302@collabora.co.uk> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hi Lee, On 22/09/15 21:34, Lee Jones wrote: > On Mon, 21 Sep 2015, Emilio L?pez 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 L?pez >> --- >> >> 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