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 E2D67D3F082 for ; Wed, 28 Jan 2026 15:43:34 +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=FvHKA+K7TUM65OMddStf3ba4SlICuMtJpdIRzvLQ96k=; b=ubUDHkV/QDlZN9JOVvn4IdejWe nuG/u+dse+Fmkp6fmhasB9fKcMK6LU39nxz+Knv5g0pY5RQign0tN/cghV91k7vWwdxdQYt25hvzB F9SSYtFKvy4Pta+r1dZpa+IKNEoVSr+wLFBQyYP96rBOICkTwx6amflkYK2hc7aTL8tWg5nWLIyA7 65dYass+BtPjUiTFoy87uEkmSXDGFzJ3oovINzDNUJvqoKrLRuY2KvPZ7MfdxwnRqxf4hxPaHFSDw LIgV+1lp3ahp8yFXd0h6Z3O3vUO1vBKHhYBDAmCNtdO0TG5kXZdgWE29KSXpUzv7aWfsC4KAfYG6T sqZT9cGw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1vl7hY-0000000GJFh-3WQG; Wed, 28 Jan 2026 15:43:28 +0000 Received: from mgamail.intel.com ([192.198.163.18]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1vl7hW-0000000GJEs-1M71 for linux-arm-kernel@lists.infradead.org; Wed, 28 Jan 2026 15:43:27 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1769615006; x=1801151006; h=date:from:to:cc:subject:message-id:references: mime-version:in-reply-to; bh=KQSgejY1A/+GDVs72frruYIXekaBlGtguMeTaoWvT3Y=; b=D9EFrTG2gvhohHiVtF7DaxnmvZATkeUqcPiRe4NHwRv96QTBLXZRRMqV t5/z4tYvG1Omtz3f96zCX4GJmo0nCE4y7o1a4mA+4K7Jf14N76muLz1C4 YsIj6NS1EQ5WwEP9I13ST5rJv1f/c7oFkUhnNKbCVoq6kfRhSCpsq/DQ1 tZ0xv5nQW6JCCDAyIHgvZtcBcOAL0OUcp8tImW9RHyY/qTJi5PPa2UK01 8etoKkKzySSUmweE/6zp20vCvzU0fyc5X74a3sjmi5AK93gE2s4DVzCJA ghk17JgulHeLpAfsgnedH9EpmqTpkc5s5HkwE51t1FmAwMuna/70DJx5J A==; X-CSE-ConnectionGUID: oi50xf8jROm1j2dEu+NNEw== X-CSE-MsgGUID: OJ4r92JaSaihtlxxYm6VYw== X-IronPort-AV: E=McAfee;i="6800,10657,11685"; a="70029623" X-IronPort-AV: E=Sophos;i="6.21,258,1763452800"; d="scan'208";a="70029623" Received: from fmviesa009.fm.intel.com ([10.60.135.149]) by fmvoesa112.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 28 Jan 2026 07:43:25 -0800 X-CSE-ConnectionGUID: 8iZq+VOyQ4u7jfUKW3qguA== X-CSE-MsgGUID: yYbDE6b3S8yn2waeuq0EFw== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.21,258,1763452800"; d="scan'208";a="208735649" Received: from egrumbac-mobl6.ger.corp.intel.com (HELO localhost) ([10.245.245.57]) by fmviesa009-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 28 Jan 2026 07:43:22 -0800 Date: Wed, 28 Jan 2026 17:43:19 +0200 From: Andy Shevchenko To: Michal Simek Cc: Andrew Lunn , Krzysztof Kozlowski , Abdurrahman Hussain , Andi Shyti , Rob Herring , Krzysztof Kozlowski , Conor Dooley , info@mocean-labs.com, linux-arm-kernel@lists.infradead.org, linux-i2c@vger.kernel.org, linux-kernel@vger.kernel.org, devicetree@vger.kernel.org Subject: Re: [PATCH v6 1/7] dt-bindings: i2c: xiic: make clocks optional Message-ID: References: <20260127-i2c-xiic-v6-0-e82e2f6f657c@nexthop.ai> <20260127-i2c-xiic-v6-1-e82e2f6f657c@nexthop.ai> <20260128-remarkable-airborne-chihuahua-a1a16c@quoll> <66c7435c-a936-413e-a016-c860d448c971@amd.com> <5dc423be-c1f4-4a59-abcc-807f63b25f3f@amd.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <5dc423be-c1f4-4a59-abcc-807f63b25f3f@amd.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 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260128_074326_381470_915104FB X-CRM114-Status: GOOD ( 27.47 ) 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 Wed, Jan 28, 2026 at 04:00:30PM +0100, Michal Simek wrote: > On 1/28/26 15:45, Andy Shevchenko wrote: > > On Wed, Jan 28, 2026 at 03:34:02PM +0100, Andrew Lunn wrote: > > > On Wed, Jan 28, 2026 at 12:21:41PM +0100, Michal Simek wrote: > > > > On 1/28/26 11:37, Krzysztof Kozlowski wrote: > > > > > On Tue, Jan 27, 2026 at 09:03:55PM +0000, Abdurrahman Hussain wrote: > > > > > > The xiic driver is designed to operate without explicit clock configuration > > > > > > > > > > And if you change this in the driver, then you change bindings? > > > > > > > > > > You miss here explanation based on hardware - how does the hardware work > > > > > if nothing ticks it clocks? > > > > > > > > Hardware obviously have clock input which needs to be connected. Without it > > > > it won't work. > > > > > > Should ACPI potential limitations be making the DT description less > > > accurate? > > > > > > Would it not be better that the driver has an DT binding and an ACPI > > > binding? Where there are common properties, common functions can be > > > used to retrieve them. However, if ACPI lacks usable clocks, use the > > > of_ method to get the clock from DT, and skip it for ACPI. > > > > Why should we use of_ methods? If this is required we can check the type of > > fwnode and act accordingly, but I think this should go deeper into some > > treewide available helpers, because now some drivers repeat the mantra. > > > > But how do the driver get the clock frequency (if needed for some register > > settings and/or calculations)? DT seems to have well established property > > 'clock-frequency' for that. Can we consider it as "ACPI binding" as well? > > "clock-frequency" property in i2c is used for selecting i2c speed 100/400kHz. > > Clock frequency in this driver is about describing clock coming to IP itself. > Documentation/devicetree/bindings/i2c/xlnx,xps-iic-2.00.a.yaml Ah, I see, then is_of_node() probably is the compromise how to deal with this setup. -- With Best Regards, Andy Shevchenko