From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bo Shen Subject: Re: [PATCH] i2c: change the id to let the i2c device work Date: Fri, 12 Oct 2012 14:42:37 +0800 Message-ID: <5077BBDD.4010004@atmel.com> References: <1350009258-10044-1-git-send-email-voice.shen@atmel.com> <20121012044042.GI11726@opensource.wolfsonmicro.com> <5077A33E.4080801@atmel.com> <20121012051419.GJ11726@opensource.wolfsonmicro.com> <5077AE8C.5040605@atmel.com> <20121012055301.GM11726@opensource.wolfsonmicro.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20121012055301.GM11726-yzvPICuk2AATkU/dhu1WVueM+bqZidxxQQ4Iyu8u01E@public.gmane.org> Sender: linux-i2c-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Mark Brown , hskinnemoen-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org Cc: linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, nicolas.ferre-AIFe0yeh4nAAvxtiuMwx3w@public.gmane.org, plagnioj-sclMFOaUSTBWk0Htik3J/w@public.gmane.org List-Id: linux-i2c@vger.kernel.org On 10/12/2012 13:53, Mark Brown wrote: > On Fri, Oct 12, 2012 at 01:45:48PM +0800, Bo Shen wrote: >> On 10/12/2012 13:14, Mark Brown wrote: > >>> No, this still makes no sense to me. This is clearly a non-DT device >>> registration, what does DT have to do with anything here? What is the > >> Yes, this is non-DT device registration. >> As the Linux kernel code is transferring to DT which doesn't use >> platform device id. however here, modified unconsciously. So correct >> this error. > > What error and what does DT have to do with any of this? DT has no > impact on non-DT systems. Yes. This has nothing to do with DT. >>> practical problem you are seeing in your system and how does this help >>> with it? > >> In non-DT kernel, we use platform device id to distinguish between >> each device. > >> So, in this case, if the id = -1, i2c core will dynamically assign a >> bus id to this bus when running, the dynamically assigned bus id is >> unknown when writing the code. So, when we use >> i2c_register_board_info(int busnum, ...) to register device on >> busnum. we don't know which value to be use. > > The I2C bus number assigned to the controller should be independant of > the platform device ID used to register the device; a better fix if this > is an issue would be to update the i2c-gpio driver to allow a fixed bus > number to be specified in platform data. Hi Haavard Skinnemoen, Do you have any suggestions about this? Thanks. BRs, Bo Shen