Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751522AbaKFSPb (ORCPT ); Thu, 6 Nov 2014 13:15:31 -0500 Received: from mail-wi0-f179.google.com ([209.85.212.179]:45263 "EHLO mail-wi0-f179.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751096AbaKFSP1 (ORCPT ); Thu, 6 Nov 2014 13:15:27 -0500 Message-ID: <545BBAA4.90407@linux.com> Date: Thu, 06 Nov 2014 19:15:00 +0100 From: Matthias Klein User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.2.0 MIME-Version: 1.0 To: Stephen Warren CC: linux-rpi-kernel@lists.infradead.org, lee@kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2] ARM: bcm2835: add device tree for Raspberry Pi model B+ References: <1415231123-920-1-git-send-email-matthias.klein@linux.com> <545B071E.7090007@wwwdotorg.org> In-Reply-To: <545B071E.7090007@wwwdotorg.org> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Am 06.11.2014 um 06:29 schrieb Stephen Warren: > I guess we should have separate device trees for those, since there are > some differences in the GPIO and I2C channel usage. That'd leave us with: > > bcm2835-rpi-b.dts (Pin3=GPIO0, Pin5=GPIO1, Pin13=GPIO21, I2C-0) > bcm2835-rpi-b-rev2.dts (Pin3=GPIO1, Pin5=GPIO2, Pin13=GPIO27, 12C-1) I think for these differences separate device trees are not needed. These pins are all at the moment configured as ALT0. Both I2C buses are configured for I2C, therefore I doesn't matter which one is wired to the gpio header. But for clarity it would be better to have a separate device tree for each model. When a gpio signal (which is configured in device tree as ALT0) is used as e.g. plain gpio output, does the kernel the reconfiguration from ALT0 to gpio output? Or must the gpio signal be configured as output in the device tree? Is is possible to set at the brcm,function/brcm,pins gpio definition also the voltage level of an gpio output for e.g. the LAN_RUN signal? How do we want to continue? Is my patch OK, or should I try to write a device tree for every model where every gpio signal is defined? Best regards, Matthias -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/