From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mark Rutland Subject: Re: [PATCH] nvmem: imx-ocotp: read uniq CPU ID and export as system serial number Date: Wed, 4 Oct 2017 16:44:29 +0100 Message-ID: <20171004154428.GK23092@leverpostej> References: <20171004151616.2622-1-marcus.folkesson@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20171004151616.2622-1-marcus.folkesson-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> Sender: devicetree-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Marcus Folkesson Cc: Srinivas Kandagatla , Rob Herring , devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: devicetree@vger.kernel.org On Wed, Oct 04, 2017 at 05:16:16PM +0200, Marcus Folkesson wrote: > The uniq ID is usually exported as ATAG_SERIAL but in case of > devicetrees, this information is not passed. > > The uniq ID is stored in OCOTP memory (bank 0, Word 1,2) on imx CPUs. > Read the ID and set as system serial number. > > This function is activated by setting `read-system-serial` > dt property for the imx-ocotp node. > > Signed-off-by: Marcus Folkesson > --- > > Comment: > I'm not sure if this functionality really should be in a device driver. > Maybe it should be in arch/arm/mach-imx/. However, it's not > completely wrong so I give it a shot. > > .../devicetree/bindings/nvmem/imx-ocotp.txt | 1 + > drivers/nvmem/imx-ocotp.c | 38 ++++++++++++++++++++++ > 2 files changed, 39 insertions(+) > > diff --git a/Documentation/devicetree/bindings/nvmem/imx-ocotp.txt b/Documentation/devicetree/bindings/nvmem/imx-ocotp.txt > index 70d791b03ea1..bf0cc9e5e50f 100644 > --- a/Documentation/devicetree/bindings/nvmem/imx-ocotp.txt > +++ b/Documentation/devicetree/bindings/nvmem/imx-ocotp.txt > @@ -16,6 +16,7 @@ Required properties: > > Optional properties: > - read-only: disable write access > +- read-system-serial: read uniq ID and export as system serial number. Available in /proc/cpuinfo As described, this is a pure SW option ( /proc/cpuinfo is a not a HW detail, and whether or not to export this information there is a policy. So as described, this shouldn't be in the DT. Are you just trying to describe whether hte information is available in the OCOTP memory? e.g. maybe this should be something like: - has-unique-id: OCOTP bank0, Words 1 & 2 contain a unique ID identifying the system. Thanks, Mark. -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html