From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752618AbaFJN4X (ORCPT ); Tue, 10 Jun 2014 09:56:23 -0400 Received: from mout.kundenserver.de ([212.227.126.187]:65304 "EHLO mout.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752443AbaFJN4V (ORCPT ); Tue, 10 Jun 2014 09:56:21 -0400 From: Arnd Bergmann To: Boris BREZILLON Cc: Wolfram Sang , Randy Dunlap , Maxime Ripard , Hans de Goede , Shuge , kevin@allwinnertech.com, devicetree@vger.kernel.org, linux-doc@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-i2c@vger.kernel.org Subject: Re: [PATCH v5 2/2] i2c: sunxi: add P2WI (Push/Pull 2 Wire Interface) controller support Date: Tue, 10 Jun 2014 15:54:56 +0200 Message-ID: <6454089.IP8IFVsofj@wuerfel> User-Agent: KMail/4.11.5 (Linux/3.11.0-18-generic; KDE/4.11.5; x86_64; ; ) In-Reply-To: <1402408036-5235-3-git-send-email-boris.brezillon@free-electrons.com> References: <1402408036-5235-1-git-send-email-boris.brezillon@free-electrons.com> <1402408036-5235-3-git-send-email-boris.brezillon@free-electrons.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" X-Provags-ID: V02:K0:IBAPqgjbsIyBQCHMyTdmoEFUX+vfux8YR+gekbCgiqd 1lSLMqcypQa5tXvVaHx/Loz9nglczg+INorYk7PNGgvNrug2Q4 jhoGQvln0NUIf9YY5CrdnR9ApZJGM1LtEkpkKGS4hDKE4Sjg+G zrAjnsGP93pw8GDDNgcIJGNv+oOUfn+E9GplK2MLH7xfymegGD 5qBG1uOHwmOaMX8l+IpjmhHd32tqZMKM9pjgGfdSxM0Boubxbe vQPZFjf4qcctcTq1jmmdwsWCMg0cJWw8O+X7+Jl+/NmSbGKhPc 2wk3x5gjYIgyLgLn3iX8wcdDlipnAu7xD8fKEG+Qcya5KjYh4p MTcNwDdtjKIzfshPIkk8= Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tuesday 10 June 2014 15:47:16 Boris BREZILLON wrote: > > +config I2C_SUN6I_P2WI > + tristate "Allwinner sun6i internal P2WI controller" > + depends on ARCH_SUNXI > + help > + If you say yes to this option, support will be included for the > + P2WI (Push/Pull 2 Wire Interface) controller embedded in some sunxi > + SOCs. > + The P2WI looks like an SMBus controller (which supports only byte > + accesses), except that it only supports one slave device. > + This interface is used to connect to specific PMIC devices (like the > + AXP221). > + Sorry for the stupid question, but why is this an i2c driver if the hardware protocol is completely different? I understand that a lot of devices can be driven using either spi or i2c, and we have two sets of {directories,maintainers,bus_types,...} for them. Your description sounds like this is a separate option that isn't any closer to i2c than it is to spi. Would it perhaps be better to expose it only as a regmap rather than an i2c host? Arnd