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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 51E44C38159 for ; Wed, 18 Jan 2023 08:52:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229469AbjARIwM (ORCPT ); Wed, 18 Jan 2023 03:52:12 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53462 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229897AbjARIsf (ORCPT ); Wed, 18 Jan 2023 03:48:35 -0500 Received: from mail.3ffe.de (0001.3ffe.de [IPv6:2a01:4f8:c0c:9d57::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 011E4392BF; Wed, 18 Jan 2023 00:02:10 -0800 (PST) Received: from mwalle01.kontron.local. (unknown [213.135.10.150]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mail.3ffe.de (Postfix) with ESMTPSA id AC0D0D5D; Wed, 18 Jan 2023 09:02:07 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=walle.cc; s=mail2022082101; t=1674028927; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=q4LtkWQwj+s5wRr9ftmaGPFVQWqkH/zbHMQ6iAuaZCk=; b=KzMwo29z2YN5Fh3BND3jQ1EzGgDVcfwgB43ZKWFNqdLmMRudSFoliRpzicnJQPrnkCW8Ha Kjyq3ICId+Gzeg1VMP+/AZ/NAsEZOa7RBIzUFt74X2scq2ycM/HJJO6ezCVZ4c5lswoYXo bRyAa7FiBncPohpKUxD0j5sd3TlXJBZ1vBjbpaqfVcxSLIUVSmI+NnsontrtuUBdqHg76I kYcgVoegHfDMhshDekkkZ5a0LHCZRRR21imc3tSZXkFMx/0+BdVjRiMvHRFq3KVPk4umgX fm8x+yq2/bG11dNCIDi7Iol7aoa1dap05dCnFr3ucEGPZI2kZ4IyJfcY8cWrBA== From: Michael Walle To: han.xu@nxp.com Cc: broonie@kernel.org, dev@kicherer.org, devicetree@vger.kernel.org, krzysztof.kozlowski+dt@linaro.org, krzysztof.kozlowski@linaro.org, linux-spi@vger.kernel.org, robh@kernel.org, michael@walle.cc Subject: Re: [PATCH 1/2] spi: dt-bindings: spi-fsl-qspi: add optional sampling-delay Date: Wed, 18 Jan 2023 09:01:59 +0100 Message-Id: <20230118080159.112295-1-michael@walle.cc> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20230117210500.oimf4yjkkqh3o4hi@umbrella> References: <20230117210500.oimf4yjkkqh3o4hi@umbrella> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Spam: Yes Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org From: "han.xu" Hi, >>> unfortunately, the rx-sample-delay-ns property does not fit here, as we >>> can only delay >>> the sampling point between zero and three "half cycles" (or edges), not >>> by an arbitrary >>> number of nanoseconds. >> >> Why this is a problem for FSL but not for other platforms having exactly >> the same constraints/property? > > Please use the common delay in DT and calculate to half cycle in driver, we have > the similar discussion before for fspi controller delay settings. Do you mean [1]? There my suggestion was to use a -degrees property (because it doesn't depend on the frequency). There wasn't any follow-up, or did I miss something? -michael [1] https://lore.kernel.org/linux-spi/62f113a0cdb0d58bf04ab0b274912eb7@walle.cc/