From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752269AbbBQWWT (ORCPT ); Tue, 17 Feb 2015 17:22:19 -0500 Received: from mail-ob0-f170.google.com ([209.85.214.170]:56478 "EHLO mail-ob0-f170.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751522AbbBQWWS (ORCPT ); Tue, 17 Feb 2015 17:22:18 -0500 MIME-Version: 1.0 X-Originating-IP: [2620:0:1000:157d:bc:f854:c351:144c] In-Reply-To: <1424059156.21410.38.camel@kernel.crashing.org> References: <1424059156.21410.38.camel@kernel.crashing.org> Date: Tue, 17 Feb 2015 14:22:17 -0800 Message-ID: Subject: Re: [PATCH 2/2] drivers/core/of: Add symlink to device-tree from devices with an OF node From: Olof Johansson To: Benjamin Herrenschmidt Cc: Rob Herring , Grant Likely , "devicetree@vger.kernel.org" , "linux-kernel@vger.kernel.org" , Arnd Bergmann Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, Feb 15, 2015 at 7:59 PM, Benjamin Herrenschmidt wrote: > So I've been annoyed lately with having a bunch of devices such as i2c > eeproms (for use by VPDs, server world !) and other bits and pieces that > I want to be able to identify from userspace, and possibly provide > additional data about from FW. > > Basically, it boils down to correlating the sysfs device with the OF > tree device node, so that user space can use device-tree info such as > additional "location" or "label" (or whatever else we can come up with) > properties to identify a given device, or get some attributes of use > about it, etc... > > Now, so far, we've done that in some subsystem in a fairly ad-hoc basis > using "devspec" properties. For example, PCI creates them if it can > correlate the probed device with a DT node. Some powerpc specific busses > do that too. > > However, i2c doesn't and it would be nice to have something more generic > since technically any device can have a corresponding device tree node > these days. > > This patch achieves this by adding an "of_node" symlink to devices that > have a non-NULL dev->of_node pointer. > > Signed-off-by: Benjamin Herrenschmidt Concept: Acked-by: Olof Johansson We've come across similar needs on product, and always had to do some less-than-optimal alternate solution. This seems like a good idea to me. -Olof