From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jason Gunthorpe Subject: Re: [PATCH] Documentation: tpm: Adds the TPM device tree node documentation Date: Fri, 2 Sep 2016 11:06:13 -0600 Message-ID: <20160902170613.GA5024@obsidianresearch.com> References: <1472532277-21933-1-git-send-email-nayna@linux.vnet.ibm.com> <20160902145121.GA9636@rob-hp-laptop> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <20160902145121.GA9636@rob-hp-laptop> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: tpmdd-devel-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org To: Rob Herring Cc: mark.rutland-5wv7dgnIgG8@public.gmane.org, devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, ijc+devicetree-KcIKpvwj1kUDXYZnReoRVg@public.gmane.org, pawel.moll-5wv7dgnIgG8@public.gmane.org, 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, galak-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org List-Id: devicetree@vger.kernel.org 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. 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? 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 ------------------------------------------------------------------------------