From mboxrd@z Thu Jan 1 00:00:00 1970 From: stigge@antcom.de (Roland Stigge) Date: Sun, 30 Sep 2012 17:09:58 +0200 Subject: [PATCH RFC 1/2] gpio: Add a block GPIO API to gpiolib In-Reply-To: References: <1348780923-27428-1-git-send-email-stigge@antcom.de> <50682402.8020402@antcom.de> Message-ID: <506860C6.5020408@antcom.de> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hi Stijn, On 30/09/12 16:52, Stijn Devriendt wrote: >> One question: How did you solve the one-value-per-file in the sysfs >> interface? >> > By exporting the group as a whole: > /sys/.../gpiogroup248/value > where value contains a decimal representing the group value. > Again, this respects the ordering of the pins: > > Actual pins: 0x2D (b 0010 1101) > Selected pins: 6 3 0 1 > Readout: 6 (b 0 1 1 0) > > The export sysfs file does, however, accept multiple gpio IDs for groups. > Not sure if this is a 'violation' per se... If I understand correctly, it's a violation (single-value should hold for read and write). To solve it, I have the following in mind: /sys/.../gpiogroupXXX/ contains files "bit0" ... "bit31" which contain a gpio number each, empty if "unconnected". Roland From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751197Ab2I3PKJ (ORCPT ); Sun, 30 Sep 2012 11:10:09 -0400 Received: from antcom.de ([188.40.178.216]:52635 "EHLO chuck.antcom.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750797Ab2I3PKI (ORCPT ); Sun, 30 Sep 2012 11:10:08 -0400 Message-ID: <506860C6.5020408@antcom.de> Date: Sun, 30 Sep 2012 17:09:58 +0200 From: Roland Stigge Organization: ANTCOM Open Source Research and Development User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:10.0.7) Gecko/20120922 Icedove/10.0.7 MIME-Version: 1.0 To: Stijn Devriendt CC: grant.likely@secretlab.ca, linus.walleij@linaro.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, w.sang@pengutronix.de, jbe@pengutronix.de, Jean-Christophe PLAGNIOL-VILLARD , bgat@billgatliff.com Subject: Re: [PATCH RFC 1/2] gpio: Add a block GPIO API to gpiolib References: <1348780923-27428-1-git-send-email-stigge@antcom.de> <50682402.8020402@antcom.de> In-Reply-To: X-Enigmail-Version: 1.4.1 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Stijn, On 30/09/12 16:52, Stijn Devriendt wrote: >> One question: How did you solve the one-value-per-file in the sysfs >> interface? >> > By exporting the group as a whole: > /sys/.../gpiogroup248/value > where value contains a decimal representing the group value. > Again, this respects the ordering of the pins: > > Actual pins: 0x2D (b 0010 1101) > Selected pins: 6 3 0 1 > Readout: 6 (b 0 1 1 0) > > The export sysfs file does, however, accept multiple gpio IDs for groups. > Not sure if this is a 'violation' per se... If I understand correctly, it's a violation (single-value should hold for read and write). To solve it, I have the following in mind: /sys/.../gpiogroupXXX/ contains files "bit0" ... "bit31" which contain a gpio number each, empty if "unconnected". Roland