From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 6E3FC301717; Wed, 28 Jan 2026 15:43:26 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.198.163.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769615009; cv=none; b=gfcSbNTkOv1AxZ7JsOvii0fO1Dis8MQr52bWE+w/tDwz5LGbj5SlDRbaRWvZJGfW9hCM0i6dMXV1VKcBsiKkgyH7883W0+n1W+PddxUt+QBgWpcQ8V98izBuDFXNqwDLF2jWAqg9AfjIGbXJHk+zAlfE3Y3ul6YqRH3qVbR2D3w= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769615009; c=relaxed/simple; bh=KQSgejY1A/+GDVs72frruYIXekaBlGtguMeTaoWvT3Y=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=mU8fytGAWi6sHzq1iyBH4wj+nrVlFWPCYYzL6y69IhgBQ/v+fRVeOXR4JWMMdMe8/cdJIxeen3DA2QHIgaDTumgEZ9a0GJPrhadSEmEm0Igjgia+eWF6zZVDfdcj3aLKkzgkqbIL1YDempaSUy9mXOh9pOPzxI+9P4CuFSrm+i4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com; spf=pass smtp.mailfrom=intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=LEYerdTu; arc=none smtp.client-ip=192.198.163.18 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="LEYerdTu" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1769615007; x=1801151007; h=date:from:to:cc:subject:message-id:references: mime-version:in-reply-to; bh=KQSgejY1A/+GDVs72frruYIXekaBlGtguMeTaoWvT3Y=; b=LEYerdTuuSaznBkN9+1sNU1W2ZCFAX1PreVXRF8gwIvviAc9UeyOPazm w2DMYXKq+Z5cx8dT+P2x/Kkk5AJkkj9ImrK69/NokdssSbMFmCCXgivgl e+4RlKAuR6AiHQxXS11uHsWh9Dj5KX+DuH8t9oWRTxf3Zk4gYdE97J/DN UJwbtMIR9luWmaT27m2AUJT5bDJJhZozK3sJxy5VWDoLlMVK4no+qbFfs 4oiOpCwijxC+xUb/lJdT23lMYPmuT4HM70fBdY9NJiarZ7b57oHH9lXdn L2Wzgc0gQ+KYmpDb2lr7+UaTIuaDl54XwmJO9oM76X19xEARLto6Ig80I A==; X-CSE-ConnectionGUID: +NYBBRYCSi6TH3hMaxdAsg== X-CSE-MsgGUID: X7fuzfncRky13C7Q6o3sYg== X-IronPort-AV: E=McAfee;i="6800,10657,11685"; a="70029621" X-IronPort-AV: E=Sophos;i="6.21,258,1763452800"; d="scan'208";a="70029621" 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> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: 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 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