From patchwork Wed Jul 4 12:36:38 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andreas Klinger X-Patchwork-Id: 10506757 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 07090601D7 for ; Wed, 4 Jul 2018 12:37:23 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id EF47928BFA for ; Wed, 4 Jul 2018 12:37:22 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id E326A28C3A; Wed, 4 Jul 2018 12:37:22 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00, MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 8567728BFA for ; Wed, 4 Jul 2018 12:37:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934546AbeGDMhV (ORCPT ); Wed, 4 Jul 2018 08:37:21 -0400 Received: from mout.kundenserver.de ([212.227.126.134]:48934 "EHLO mout.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933777AbeGDMhU (ORCPT ); Wed, 4 Jul 2018 08:37:20 -0400 Received: from localhost ([91.52.186.254]) by mrelayeu.kundenserver.de (mreue001 [212.227.15.167]) with ESMTPSA (Nemesis) id 0MgTUE-1fnO2z0ud4-00NjIr; Wed, 04 Jul 2018 14:36:39 +0200 Date: Wed, 4 Jul 2018 14:36:38 +0200 From: Andreas Klinger To: jic23@kernel.org, knaack.h@gmx.de, lars@metafoo.de, pmeerw@pmeerw.net, robh+dt@kernel.org, mark.rutland@arm.com, mchehab@kernel.org, davem@davemloft.net, gregkh@linuxfoundation.org, akpm@linux-foundation.org, linus.walleij@linaro.org, rdunlap@infradead.org, devicetree@vger.kernel.org, linux-iio@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v4 1/3] iio: hx711: add clock-frequency property in DT Message-ID: <20180704123638.GA30535@arbeit> MIME-Version: 1.0 Content-Disposition: inline User-Agent: Mutt/1.5.23 (2014-03-12) X-Provags-ID: V03:K1:jnm4tvqBvGrTT7lJO2e7XKBe21wzvEJyvHrAY1957k2XFo5/UgJ 3oY7FQFTHM7+MZ1K8u5XaGWQAHVOw32HzhomxCx21w2ZEv3e+k3dzNW2Nizx5h+dqCnoYry O1YgHBISJ0GIX9XIlxx9hQJlW4iOIAnIJrN1mF8uj5AChkD1t0qwI37giKDi8PSkRZ68usz UE2T1NvhV/cA7m7/VyUMg== X-UI-Out-Filterresults: notjunk:1; V01:K0:cB7H7PW1VME=:ZkmKBCy8KCtDej/GD+W62+ 2cQsFLKJnTv2R4533YNgBsbRVQKoEgRrIz8rPFqEumsDNVi+l/z0xW3theZX8AtYLR7sgUzUK kgtU7wu1u4xB4ldv+edUfdC3DEWaWS8ypAyI4YxoLtmgQYrDNTXQq3vUq9tO0XFHwOF1ScVFA x1wK0gRZTijk1G8WvVGNoIwCEMJXrPr1MM0gdmoBiT0VHllwFPBGyYYpLJexWpDSVYzhZGFrK lrcJ4i+R68PHp1FkFzTTQbmJj4wfZcX7cysZLsrFfNvR9CkaomW75qD8jhM1H23lg98X7QTDT 3weAcGzhbtJX8Q8xQ58NBGc3SdkqrttuaryHK9Br3LagN7HVLmCjJcGXVU/90OwI1Cj9UbksW RQtcl+SHqRi0Gm0VaR6BBg5vsMJ/i3gt7NyTIdZQFMYX3gQN5ecCW6GbsPBJHFSRNqiFORfdj N0+s8mC2fyUwic1JZ+Wut5O45W5aZIB/tg7yv7T6ZhVyszBPiko638tW/yILoUhW+t44BEPN0 umk+uzM25fTxkSmGMqs+nVTPEgaP2PggXD7owzxKsApOZ9ydgDM8UvWIYMQte6tnbPOYdcjlx tPkqqvgB3kJu8clSzGYW0fK2horwxTHGBbwwj+5HmZIlpJAMgyi8E2ePLgCuxfWuaAq/4IsEM OXio7neAPOZ0tErb/ngUkApfVVTu4qXRVT3C8rvtZmpe3CS7ivi+weftoJ5rzDVWv6fo= Sender: linux-iio-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-iio@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Add clock-frequency property for hx711 ADC This is the frequency of PD_SCK. It affects only the high value duration since low value duration is not relevant and we are not able to switch faster than the minimum duration specified. After PD_SCK goes high DOUT is read just before PD_SCK goes down again. This is necessary because of parasitic capacities on the wiring. Signed-off-by: Andreas Klinger --- Documentation/devicetree/bindings/iio/adc/avia-hx711.txt | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/Documentation/devicetree/bindings/iio/adc/avia-hx711.txt b/Documentation/devicetree/bindings/iio/adc/avia-hx711.txt index b3629405f568..4bee51d536e1 100644 --- a/Documentation/devicetree/bindings/iio/adc/avia-hx711.txt +++ b/Documentation/devicetree/bindings/iio/adc/avia-hx711.txt @@ -8,11 +8,21 @@ Required properties: See Documentation/devicetree/bindings/gpio/gpio.txt - avdd-supply: Definition of the regulator used as analog supply +Optional properties: + - clock-frequency: Frequency of PD_SCK + This setting affects the duration of the high value + phase of the clock (PD_SCK). The low value phase is + not affected since it is not relevant for the + measurement. + Minimum value allowed is 20 kHz because of maximum + high time of 50 microseconds. + Example: weight@0 { compatible = "avia,hx711"; sck-gpios = <&gpio3 10 GPIO_ACTIVE_HIGH>; dout-gpios = <&gpio0 7 GPIO_ACTIVE_HIGH>; avdd-suppy = <&avdd>; + clock-frequency = <100000>; };