From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756515Ab2FNS5s (ORCPT ); Thu, 14 Jun 2012 14:57:48 -0400 Received: from mail-ee0-f46.google.com ([74.125.83.46]:38873 "EHLO mail-ee0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754025Ab2FNS5h (ORCPT ); Thu, 14 Jun 2012 14:57:37 -0400 Message-ID: <4FDA341C.8010501@linaro.org> Date: Thu, 14 Jun 2012 19:57:32 +0100 From: Lee Jones User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:11.0) Gecko/20120410 Thunderbird/11.0.1 MIME-Version: 1.0 To: Mark Brown CC: Linus Walleij , linus.walleij@stericsson.com, arnd@arndb.de, linux-kernel@vger.kernel.org, grant.likely@secretlab.ca, linux-i2c@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH 09/14] i2c: Add Device Tree support to the Nomadik I2C driver References: <1339428307-3850-1-git-send-email-lee.jones@linaro.org> <1339428307-3850-10-git-send-email-lee.jones@linaro.org> <4FD6F0E8.5040606@linaro.org> <4FD83AAD.2010701@linaro.org> <4FD88761.9050703@linaro.org> <20120614183636.GB30185@sirena.org.uk> In-Reply-To: <20120614183636.GB30185@sirena.org.uk> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 14/06/12 19:36, Mark Brown wrote: > On Wed, Jun 13, 2012 at 01:28:17PM +0100, Lee Jones wrote: > >> Device Tree. However, we have just as much control by keeping them >> in separate structs in the C file and selecting the right one using >> the compatible sting. > > You're not understanding Linus' point. The compatible string isn't > useful here because properties like the maximum clock rate of the bus > depend on the board design, not the silicon. The controller may be > perfectly happy to run at a given rate but other devices on the bus or > the electrical engineering of the PCB itself may restrict this further. And you're not understanding mine. ;) You can have multiple compatible strings for a single driver. Which one you reference from the Device Tree will dictate which group of settings are used, including variation of clock rates. -- Lee Jones Linaro ST-Ericsson Landing Team Lead M: +44 77 88 633 515 Linaro.org │ Open source software for ARM SoCs Follow Linaro: Facebook | Twitter | Blog From mboxrd@z Thu Jan 1 00:00:00 1970 From: Lee Jones Subject: Re: [PATCH 09/14] i2c: Add Device Tree support to the Nomadik I2C driver Date: Thu, 14 Jun 2012 19:57:32 +0100 Message-ID: <4FDA341C.8010501@linaro.org> References: <1339428307-3850-1-git-send-email-lee.jones@linaro.org> <1339428307-3850-10-git-send-email-lee.jones@linaro.org> <4FD6F0E8.5040606@linaro.org> <4FD83AAD.2010701@linaro.org> <4FD88761.9050703@linaro.org> <20120614183636.GB30185@sirena.org.uk> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: <20120614183636.GB30185-GFdadSzt00ze9xe1eoZjHA@public.gmane.org> Sender: linux-i2c-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Mark Brown Cc: Linus Walleij , linus.walleij-0IS4wlFg1OjSUeElwK9/Pw@public.gmane.org, arnd-r2nGTMty4D4@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, grant.likely-s3s/WqlpOiPyB63q8FvJNQ@public.gmane.org, linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org List-Id: linux-i2c@vger.kernel.org On 14/06/12 19:36, Mark Brown wrote: > On Wed, Jun 13, 2012 at 01:28:17PM +0100, Lee Jones wrote: > >> Device Tree. However, we have just as much control by keeping them >> in separate structs in the C file and selecting the right one using >> the compatible sting. > > You're not understanding Linus' point. The compatible string isn't > useful here because properties like the maximum clock rate of the bus > depend on the board design, not the silicon. The controller may be > perfectly happy to run at a given rate but other devices on the bus o= r > the electrical engineering of the PCB itself may restrict this furthe= r. And you're not understanding mine. ;) You can have multiple compatible strings for a single driver. Which one= =20 you reference from the Device Tree will dictate which group of settings= =20 are used, including variation of clock rates. --=20 Lee Jones Linaro ST-Ericsson Landing Team Lead M: +44 77 88 633 515 Linaro.org =E2=94=82 Open source software for ARM SoCs =46ollow Linaro: Facebook | Twitter | Blog From mboxrd@z Thu Jan 1 00:00:00 1970 From: lee.jones@linaro.org (Lee Jones) Date: Thu, 14 Jun 2012 19:57:32 +0100 Subject: [PATCH 09/14] i2c: Add Device Tree support to the Nomadik I2C driver In-Reply-To: <20120614183636.GB30185@sirena.org.uk> References: <1339428307-3850-1-git-send-email-lee.jones@linaro.org> <1339428307-3850-10-git-send-email-lee.jones@linaro.org> <4FD6F0E8.5040606@linaro.org> <4FD83AAD.2010701@linaro.org> <4FD88761.9050703@linaro.org> <20120614183636.GB30185@sirena.org.uk> Message-ID: <4FDA341C.8010501@linaro.org> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 14/06/12 19:36, Mark Brown wrote: > On Wed, Jun 13, 2012 at 01:28:17PM +0100, Lee Jones wrote: > >> Device Tree. However, we have just as much control by keeping them >> in separate structs in the C file and selecting the right one using >> the compatible sting. > > You're not understanding Linus' point. The compatible string isn't > useful here because properties like the maximum clock rate of the bus > depend on the board design, not the silicon. The controller may be > perfectly happy to run at a given rate but other devices on the bus or > the electrical engineering of the PCB itself may restrict this further. And you're not understanding mine. ;) You can have multiple compatible strings for a single driver. Which one you reference from the Device Tree will dictate which group of settings are used, including variation of clock rates. -- Lee Jones Linaro ST-Ericsson Landing Team Lead M: +44 77 88 633 515 Linaro.org ? Open source software for ARM SoCs Follow Linaro: Facebook | Twitter | Blog