From mboxrd@z Thu Jan 1 00:00:00 1970 From: Nayna Subject: Re: [tpmdd-devel] [PATCH] Documentation: tpm: Adds the TPM device tree node documentation Date: Wed, 28 Sep 2016 14:10:55 +0530 Message-ID: <57EB8217.40202@linux.vnet.ibm.com> References: <1472532277-21933-1-git-send-email-nayna@linux.vnet.ibm.com> <20160902145121.GA9636@rob-hp-laptop> <20160902170613.GA5024@obsidianresearch.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Sender: devicetree-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Rob Herring , Jason Gunthorpe Cc: Mark Rutland , "devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , Pawel Moll , Ian Campbell , "wsa-z923LK4zBo2bacvFa/9K2g@public.gmane.org" , tpmdd-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org, gcwilson-r/Jw6+rmf7HQT0dZR+AlfA@public.gmane.org, "linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , Kumar Gala List-Id: devicetree@vger.kernel.org On 09/02/2016 11:27 PM, Rob Herring wrote: > On Fri, Sep 2, 2016 at 12:06 PM, Jason Gunthorpe > wrote: >> On Fri, Sep 02, 2016 at 09:51:21AM -0500, Rob Herring wrote: >>>> +- linux,sml-base : base address of the Event Log. It is a physical address. >>>> + sml stands for shared memory log. >>> >>> How is it a physical address on an i2c device? Why 2 cells (which needs >>> to be documented also)? >> >> To be clear, as I understand it, this mechanism is a hand off from the >> boot firmware to Linux. >> >> The boot firmware talks i2c to the device, does some stuff, writes it >> to memory and then linux reads that stuff. I agree it seems crazy to >> include a random physical address like that. > > I'd put that in reserved-memory then if designing this from scratch... Thanks for the review comments. Yes, it is in reserved-memory. I modified the explanation for linux,sml-base property to be more descriptive now in my v2 version of the patch, posted just now. > > Must not be completely random as somehow the kernel doesn't use that memory. > >> The linux,sml-* names appear to have been used by IBM for a long time >> on their enterprise PPC platforms (see drivers/char/tpm/tpm_of.c), so >> I've expected we have to keep them? > > Yes. I wasn't aware of that. > >> I asked Nayna to document this stuff IBM is doing so the rest of us >> in TPM land can have a hope of maintaining it... >> >> Jason >> -- >> 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 > -- 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