From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E1739C43331 for ; Tue, 24 Mar 2020 10:34:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BEB24208D5 for ; Tue, 24 Mar 2020 10:34:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727270AbgCXKev (ORCPT ); Tue, 24 Mar 2020 06:34:51 -0400 Received: from sauhun.de ([88.99.104.3]:48924 "EHLO pokefinder.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727241AbgCXKev (ORCPT ); Tue, 24 Mar 2020 06:34:51 -0400 Received: from localhost (p54B3339A.dip0.t-ipconnect.de [84.179.51.154]) by pokefinder.org (Postfix) with ESMTPSA id D13B92C08EF; Tue, 24 Mar 2020 11:34:48 +0100 (CET) Date: Tue, 24 Mar 2020 11:34:48 +0100 From: Wolfram Sang To: Tomasz Figa Cc: Bibby Hsieh , Bartosz Golaszewski , linux-i2c , Nicolas Boichat , srv_heupstream , Rob Herring , Mark Rutland , linux-devicetree , "Rafael J . Wysocki" Subject: Re: [PATCH v12 1/2] dt-binding: i2c: add bus-supply property Message-ID: <20200324103448.GE1134@ninjato> References: <20200306034946.11223-1-bibby.hsieh@mediatek.com> <20200306034946.11223-2-bibby.hsieh@mediatek.com> <20200322130710.GA1091@ninjato> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="tVmo9FyGdCe4F4YN" Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) Sender: devicetree-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org --tVmo9FyGdCe4F4YN Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable > > > +- bus-supply > > > + phandle to the regulator that provides power to i2c. > > > > I think this is not clear enough. I assume it means the regulator for > > driving SCL/SDA? In the coverletter you mention also an EEPROM. In your > > case, this is driven by the same regulator? I am skeptical we can > > abstract it like this because I2C devices could be driven by various > > regulators in the system, so there couldn't be one "bus regulator". The > > regulator for the EEPROM should be described in the EEPROM node. So, > > this "bus supply" is only for driving SCL/SDA? >=20 > In our case the bus-supply regulator drives the voltage rail to which > SCL/SDA are pulled up and there is an EEPROM on the bus, powered by > yet another rail. There is also another slave on the bus which uses > the same regulator as the bus-supply for its own power. >=20 > In other words, bus-supply only ensures that SCL and SDA are in a > usable state. Other consumers need to refer to the regulator in their > own supplies if they need it for their own power. >=20 > Does this answer your questions? Yes, this was exactly what I was assuming. So, I think the above documentation should be changed: s|i2c|SCL/SDA| D'accord? --tVmo9FyGdCe4F4YN Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAABCgAdFiEEOZGx6rniZ1Gk92RdFA3kzBSgKbYFAl554kQACgkQFA3kzBSg KbamcA/+Ll60/Efzo6FG3APE0g6ZjxtUBgbCskbrOq6AAiExxWU0zzl2zcvkimxm EzB4MMQDk7XBRnr8IeBNOHgT9F7txegCzrSzCTV8j0peut5akg385S8heeM5b9e+ udCKQahb2tb8vOCZFOTn9OoguZ+VDNhOYCGIoBcgUCA/YWcuomaxt/VPACI+E558 TWqhouadPIqQiRLGuF6N+Ya8Tri9i6cURoYa1uZKL/bsnxKc0TkcWiiOzYXmB+Fu I6uNg5XJxRzIvYDAeMuWxvUOazNcdJldc1l+neD3HKhKQs+OKyVl25JD7tLpgZNU CHQHoItGULjh7sapaG3BbjkW//SHTumw6G6JBYNrjrzA3Tr6gv6+dymXyPKp62sA 9XFwguFD2LntFyVBsuBs0tN8jycZNkp0wgEXnTetn2gFQP70lXby6wlhTkUahEHf WIcDERSPKv7UleKiwaZx9p3KMZisxMMdJZjArKwbLE7xu0iFjwhepD4D4wlmHrT+ dDVLJJJDShtwpTqSFsGjdo6xDT5Hzx7Vdv/dSBtLk9P+OSj3AwgVA3bG+PnXUzLW C5WvW28kFg78c49B7vlYVnNcoxhIJuuloiCeKGXwjba0OZ1nRjHi37VC5Q4S43Mu DpVsDnjrkImZub+ijqjHgfLXL5OSV/NVDjrVsCnq8zZlbkHgGgM= =/K3S -----END PGP SIGNATURE----- --tVmo9FyGdCe4F4YN--