From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-lb0-f175.google.com (mail-lb0-f175.google.com [209.85.217.175]) by yocto-www.yoctoproject.org (Postfix) with ESMTP id 0E60FE013A7 for ; Wed, 14 Aug 2013 09:12:57 -0700 (PDT) Received: by mail-lb0-f175.google.com with SMTP id 13so7005515lba.20 for ; Wed, 14 Aug 2013 09:12:56 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20120113; h=x-gm-message-state:message-id:date:from:user-agent:mime-version:to :cc:subject:references:in-reply-to:content-type :content-transfer-encoding; bh=MnUcGNHXOhPO6oQvaKbsk5tcLjJHL7uJy48nOkEJgpQ=; b=V3I7LYb8HEbFYmVkWO6MO1zv0WfrhYzgQhg44yBIw7zL8e/oKaukFQNF9ATzox0CWS q//qRKQuJamqLkNHqe1Y5eLxkZ+fDEwfvxiC9YgA2NVBVQl6BfwKRJZ4Q8jXwJp+ApI1 9FeIk67V8tYeDEaMkiKWxKVwtJSrq4bsf/zBCEcjRrKZ5mZaaLOR8fbEh+fSRZW590XY gJqU5Z2e74xeZHB6TTfyuOLraICGF2mZp0cJDH+ax0qcw5TsPBwb+WQvNjDWkSwMyUBg cYOFgxSP50pCdabfpSzxlrdwVlOFXtD3FYB+YhJmbmjPWNYPtIHXrv01yf6jqumxFIhD 4z8A== X-Gm-Message-State: ALoCoQma468v/gDmQ4IWcbRW689l6lIbRf3pgDNsoLOogeOErBCn+uNjqxl9qnzrO1ZEZxaBnrB4 X-Received: by 10.112.33.205 with SMTP id t13mr8769568lbi.22.1376496776128; Wed, 14 Aug 2013 09:12:56 -0700 (PDT) Received: from [192.168.0.15] ([70.96.116.236]) by mx.google.com with ESMTPSA id db5sm16468932lac.10.2013.08.14.09.12.54 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Wed, 14 Aug 2013 09:12:55 -0700 (PDT) Message-ID: <520BAC84.3020906@boundarydevices.com> Date: Wed, 14 Aug 2013 09:12:52 -0700 From: Eric Nelson User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130803 Thunderbird/17.0.8 MIME-Version: 1.0 To: Thanassis Silis References: , <520A7B28.3000604@boundarydevices.com> , <520B93F4.9060306@boundarydevices.com> In-Reply-To: Cc: "meta-freescale@yoctoproject.org" Subject: Re: speed of /dev/i2c-2 in imx6q sabre-lite X-BeenThere: meta-freescale@yoctoproject.org X-Mailman-Version: 2.1.13 Precedence: list List-Id: Usage and development list for the meta-fsl-* layers List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 14 Aug 2013 16:13:00 -0000 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Hi Thanassis, On 08/14/2013 08:40 AM, Thanassis Silis wrote: > Hi Eric, > kernel configuration is no stranger to me as I am a longtime slackware > user, but thank you for the info. It is always nice to know I have not > understood something the wrong way. > Sorry if I was being pedantic. I thought that's what you were asking and folks come in with all kinds of background. > What I do not know is how the IMX_I2C_BIT_RATE (which is 100kHz) is > related to the imxi2c_platform_data structure. > The file drivers/i2c/busses/i2c_imx.c doesn't include > arch/arm/mach-mx6/board_nitrogen6x.c (or _sabrelite.c for that matter) > or vice-versa. So is it correct to say that i2c-imx.c sets the bitrate > earlier in the boot process and then the platform specific code, > overwrites/alters that value to what is set in board_nitrogen6x.c ? Nope. The driver's "probe" routine gets handed the imxi2c_platform_data structure from the device registration procedure in board-mx6_nitrogen.c. IOW, there's a run-time path, not a compile-time path. Otherwise, every driver would need to know about every board that used it. If you look closely, all of the uses of IMX_I2C_BIT_RATE are conditional on either missing "pdata" (platform data) or a zero value for bitrate. Regards, Eric