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 A1696CCA489 for ; Tue, 26 Jul 2022 07:24:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238119AbiGZHYR (ORCPT ); Tue, 26 Jul 2022 03:24:17 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58246 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238120AbiGZHXa (ORCPT ); Tue, 26 Jul 2022 03:23:30 -0400 Received: from mail-ej1-x62b.google.com (mail-ej1-x62b.google.com [IPv6:2a00:1450:4864:20::62b]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9A57D2B619 for ; Tue, 26 Jul 2022 00:23:21 -0700 (PDT) Received: by mail-ej1-x62b.google.com with SMTP id z23so24327380eju.8 for ; Tue, 26 Jul 2022 00:23:21 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=DD0uadPhkaJ539aapAhTDeVFQH+XGwCWm7G+YfPh7fc=; b=Kba4ZDV1A/AXRgz6iEbxRwn8EqVTv2R9yv+8Q2gRza9+ZIvQtXmDpHMJ+sUhFJFMZ0 7FbNc6d3/UoKdDqyTR5suL8w6TJ5Gn4/Kz3AtA2NjJTGAKHlcxyL3aJx4A7+/5TiUfQS NxlzBAykIrKayHvDFOAKgU5Tiinpei2lR44V3d7wEJl+WEyIYRuRvQ9iG/c5gF30k3Zl UFz7H/aJUp9D6Vjh3W9yMy72PrQ2Xxh5RoEOE3cP+U8zGqLPIIyi1AHwfcGI0gIcwimM 2dsoyOJLHp+5tVE6zpTC3LAoEK7Uku2f0P0wNfD7NWfh2JBiJ8ColgXgz/u4zr4EIrTZ 1Fsw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=DD0uadPhkaJ539aapAhTDeVFQH+XGwCWm7G+YfPh7fc=; b=Emi/7f1Ih4myYcxzorxDa//Kv68iiEiw2D6WOYj4txhqxi8aKEHRObMypuzj+mthRG iqqIh8QRO2wmJVnCG1KTukasbWhSuojSGb/8WCuucNhVWQnN6oBo1XvlLtNUGkbFOLuh 6iiTBcdD5Pj5SQPtlbsWySFwBOE05yxYf+YsHFFUWYDAMPXTacbMqtJwfWNZmXRzK58Z BFTPxu2yzVNo/N+7vw2XwsrrSGukyNe8oe7DdtYsD8YubFvMGtttcyKLmiZ10nnfpFXv MxVRc6B6kerITXONEqxt+l/bpkN87BdoY6M/ZhjJFWvJX545ZtCU+Oc69mBVPwQqF9MK fGYA== X-Gm-Message-State: AJIora+Ac/A0n+1ysxgdW8FNJ68nzKWPktfIxWOkI/ECYOnzmxFoIYbK cG9hkhG94gmuxDRgIwPSEev3TaCOdYF4IE7QjbsxoWnO8cvSuQ== X-Google-Smtp-Source: AGRyM1tNXCKI2buHcvEhsS4ymiRcgoitpKwhQicSRzpI9ca8De/k6MNUhY31qEeF7NOfuZPg6YuHDk4sc/waM5l8O4g= X-Received: by 2002:a17:906:58c8:b0:6fe:91d5:18d2 with SMTP id e8-20020a17090658c800b006fe91d518d2mr13217132ejs.190.1658820199862; Tue, 26 Jul 2022 00:23:19 -0700 (PDT) MIME-Version: 1.0 References: <20220721093422.2173982-1-marcus.folkesson@gmail.com> In-Reply-To: From: Linus Walleij Date: Tue, 26 Jul 2022 09:23:08 +0200 Message-ID: Subject: Re: [PATCH 1/2] gpio: gpio-74x164: add support for CDx4HC4094 To: Andy Shevchenko Cc: Marcus Folkesson , Bartosz Golaszewski , Rob Herring , Krzysztof Kozlowski , Maxime Ripard , "open list:GPIO SUBSYSTEM" , devicetree , Linux Kernel Mailing List Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-gpio@vger.kernel.org On Tue, Jul 26, 2022 at 8:55 AM Andy Shevchenko wrote: > On Tue, Jul 26, 2022 at 12:22 AM Linus Walleij wrote: > > Well it will work, because all values come out, however *during* > > the transfer, not *after* the transfer as intended with the > > STR signal. > > No. I think you missed one little but crucial detail. The strobe is > edge, not level, while you consider CS as a level signal (only). Aha! Then it works :) > See Figure 7 and Table 9 in the datasheet you linked to. When STR is > low, the data is not changed. Maybe it's not clear in this datasheet, > I found somewhere > in a more clear table. > > > At least how I see it ...? > > If what you are saying is true, the hardware is totally broken and I > wouldn't use it. I.o.w. if the strobe passes all data when it's at low > level and latches at low-to-high, it's broken by definition in my > point of view. I have seen strobes that are level-active in my life, but if you say this one isn't then all is fine! Yours, Linus Walleij