From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 3852CC43458 for ; Mon, 13 Jul 2026 16:11:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=tidJ9fw1OYoBYaGiXNeJYbpawTJlwdZEByZ/V7kxknU=; b=1ALitNPeeo+qsfAC8Wxh8J2bZD +Uqwla10pr+/vmRhsbd7/IUx7aAatGdyEX6X4THUdg41o0lpLMjbv2sT9UF9Q4tIdpRx0kToZ6WwT v9nEUIQ16yxTpQP847xa+3Ooq3DqobSSf44oqq4GLZKPPcsougL3kpDrj+Ulk6rmxukPGpyBKIpt1 jIUkqSJCgB/Rfm+LlSdWOOZQ2TZD21jivokO4lgXwgAkwfqzrCNWGOLHU+vtph5NDcoOoE351sPWq E0cKD6NgeguOq+kB3hYGAQw+NWh58ndFbJGF0wYqO725Dx9CIrU3itpv5/t8Rw9QW8x+rEHowDC2W ZKRj0Qnw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wjJFG-00000009ukm-1QBX; Mon, 13 Jul 2026 16:11:02 +0000 Received: from mgamail.intel.com ([198.175.65.19]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1wjJFD-00000009ukL-2zB9 for linux-arm-kernel@lists.infradead.org; Mon, 13 Jul 2026 16:11:00 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1783959060; x=1815495060; h=date:from:to:cc:subject:message-id:references: mime-version:in-reply-to; bh=YZ/BOqdI0asVtPSpoTQNzl05BwwgREcjJn07zQcObpg=; b=H7UuQiWCNk5p6GHXQ5+XYNDxls7mluAsSqQTJob+SynoDrTkaO2ut5EV fdY2EW57naR6kYB9yW5eYoPjveII9Dmxl76huqQSTxiqLvA2AcR2ilRru y5FZPQ03q2K7lJQLRJZAm55/xenlx1VBkPtUVWy0oKKyREKdZsDjz9+O5 2Zs7KRYyiHQypIutJJoS4WHgcfAgKkPklUK0bBo69vjwrX2FvlckjLgxN kV0ikebqu/UzBOLP7FiHTdO/tqLh3xmUzQhUkdmGCqSNcXvKOtv+g5Tww KEt/lH+S/S2mZv86TrWE4gtwR8VaHVIPFxI4PDVAs9RM5YVvNcvf5w8GY g==; X-CSE-ConnectionGUID: swmVvkqdQ92HRqkICTy1Jw== X-CSE-MsgGUID: RAS28kbaTeaNAwtUfV1igg== X-IronPort-AV: E=McAfee;i="6800,10657,11841"; a="84536928" X-IronPort-AV: E=Sophos;i="6.25,154,1779174000"; d="scan'208";a="84536928" Received: from orviesa006.jf.intel.com ([10.64.159.146]) by orvoesa111.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 13 Jul 2026 09:10:59 -0700 X-CSE-ConnectionGUID: 853GWs/YSl+HSJAOIgZ20A== X-CSE-MsgGUID: rXLkjSZ9TLWvhbkbQGT0jw== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.25,154,1779174000"; d="scan'208";a="253858335" Received: from ijarvine-mobl1.ger.corp.intel.com (HELO localhost) ([10.245.245.88]) by orviesa006-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 13 Jul 2026 09:10:56 -0700 Date: Mon, 13 Jul 2026 19:10:54 +0300 From: Andy Shevchenko To: Marcus Folkesson Cc: Wolfram Sang , Michael Hennerich , Bartosz Golaszewski , Andi Shyti , Bartosz Golaszewski , Peter Rosin , linux-i2c@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH v11 1/7] i2c: core: add callback to change bus frequency Message-ID: References: <20260713-i2c-mux-v11-0-72bb8af8ee8c@gmail.com> <20260713-i2c-mux-v11-1-72bb8af8ee8c@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260713-i2c-mux-v11-1-72bb8af8ee8c@gmail.com> Organization: Intel Finland Oy - BIC 0357606-4 - c/o Alberga Business Park, 6 krs, Bertel Jungin Aukio 5, 02600 Espoo X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260713_091059_795678_C99A6106 X-CRM114-Status: GOOD ( 14.40 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Mon, Jul 13, 2026 at 09:19:57AM +0200, Marcus Folkesson wrote: > All devices on the same I2C bus share the same clock line and the bus > frequency has therefor be chosen so that all attached devices are able > to tolarate that clock rate. IOW, the bus speed must be set for the > slowest attached device. > > With I2C multiplexers/switches on the other hand, it would be possible > to have different "domains" that runs with different speeds. > > Prepare for such a feature by provide an optional callback function to > change bus frequency. > > As a side effect, several bus drivers keep the bus speed in a > private structure and can now have this value stored in a uniform way > instead. ... > + u32 clock_hz; /* bus clock speed */ > + int (*set_clk_freq)(struct i2c_adapter *adap, u32 clock_hz); /* Optional */ Ah, I thought you also updated to _Hz here... But no need to resend just for that, only in case of a new version for something else. (Or maybe Andi even can tweak this whilst applying...) -- With Best Regards, Andy Shevchenko