From patchwork Fri Nov 9 22:00:42 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Matheus Tavares X-Patchwork-Id: 10676587 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 0BE1914DB for ; Fri, 9 Nov 2018 22:01:33 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id ECD7B2ECCE for ; Fri, 9 Nov 2018 22:01:32 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id DFAF72F2F4; Fri, 9 Nov 2018 22:01:32 +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,DKIM_SIGNED, DKIM_VALID,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 844CC2ECCE for ; Fri, 9 Nov 2018 22:01:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728586AbeKJHoA (ORCPT ); Sat, 10 Nov 2018 02:44:00 -0500 Received: from mail-qk1-f173.google.com ([209.85.222.173]:39754 "EHLO mail-qk1-f173.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728565AbeKJHoA (ORCPT ); Sat, 10 Nov 2018 02:44:00 -0500 Received: by mail-qk1-f173.google.com with SMTP id e4so4340183qkh.6 for ; Fri, 09 Nov 2018 14:01:30 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=usp-br.20150623.gappssmtp.com; s=20150623; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=LhpxHGS44Lcj5Lch5D6YJeYb8TZ7ZrrJRAOf+39PfYk=; b=ahqEazFPXrR326X1+ybyRmOJ54W6cO27ZGRlOy4Nn929cxSXbcA6ac+BrYxLEZkiQW bCGG/IbrQo3dkvj3h9xmZSzoPKrE5ArMVbTuMoo8hg83QvLFkcF7rjoimSM9zjoazo2G /8dL8/WQVmkUIyboPHNj7Nv5wIC5zQosAZd58BMNGEelZ3KzC+EFfkUMGQVn8BD0L87w l9C3uYJD5dpLf4PM0QgmWwaLRMSg0FyNgYxbv8bTwVzijdXsRmUfTPQUHvZjDetKBw76 vZoGEE0HL+JQJOCtU4OrTpdr255YHCecMUfdEHB+05mgD4dppvY5F6BGI8SEHQv6WvZz QNrQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=LhpxHGS44Lcj5Lch5D6YJeYb8TZ7ZrrJRAOf+39PfYk=; b=SxIoaEg/N5QhyNkAxuaFpVSx81wyPWgzAYxBni5rDMOcCUbWj+5McrPRnmqAKZaFf/ J5XKGT6KlJOVqu7N3VdfK3egbj7Nho/qTWO/WV5QDnXd7JOTpx+0X5l/7cF2BraxTMED sOZd8XzhEYKLAjc2T77f28DseGFPQUpSk5RAu4VPgTkkZwfcFp1SGi7pcPV0JEEFx8C4 X2AiwZFHCf+Ucwqr7R/3O14al1p7hiyDBMVnmpFfHH+Ww9LAdCMlFXZv6s6/kb/iWBNV MxLw5UajhaMiOJuBPJm6dY25M76XrJdAscKLnktOzUfU3oYocwgr3bUHuqjMcbQYo7AK CP2A== X-Gm-Message-State: AGRZ1gJfD4tKgsgUQBzL0BIMY+vxbC4ni4EPq6I1zRSHZlGG2cYKjlDQ ylrwFO1rVLH5PwCVuRBSm9d23w== X-Google-Smtp-Source: AJdET5dfosKORZMJ/SXRBPjaQAUx4+GjI4d149fU+6gZ0txwAQIOts5VEfXZOUAkOX06qgBHKfvbQg== X-Received: by 2002:a37:2008:: with SMTP id g8mr9822709qkg.120.1541800889594; Fri, 09 Nov 2018 14:01:29 -0800 (PST) Received: from mango.spo.virtua.com.br ([2804:14c:81:942d::1]) by smtp.gmail.com with ESMTPSA id k6sm6082723qtk.41.2018.11.09.14.01.25 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 09 Nov 2018 14:01:29 -0800 (PST) From: Matheus Tavares To: Lars-Peter Clausen , Michael Hennerich , Jonathan Cameron , Hartmut Knaack , Peter Meerwald-Stadler , Greg Kroah-Hartman , Rob Herring , Mark Rutland Cc: linux-iio@vger.kernel.org, devel@driverdev.osuosl.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, Alexandru Ardelean , kernel-usp@googlegroups.com, victorcolombo@gmail.com Subject: [PATCH 4/6] dt-bindings:iio:resolver: Add docs for ad2s90 Date: Fri, 9 Nov 2018 20:00:42 -0200 Message-Id: <20181109220044.24843-5-matheus.bernardino@usp.br> X-Mailer: git-send-email 2.18.0 In-Reply-To: <20181109220044.24843-1-matheus.bernardino@usp.br> References: <20181109220044.24843-1-matheus.bernardino@usp.br> 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 This patch adds the device tree binding documentation for the ad2s90 resolver-to-digital converter. Signed-off-by: Matheus Tavares --- .../bindings/iio/resolver/ad2s90.txt | 26 +++++++++++++++++++ 1 file changed, 26 insertions(+) create mode 100644 Documentation/devicetree/bindings/iio/resolver/ad2s90.txt diff --git a/Documentation/devicetree/bindings/iio/resolver/ad2s90.txt b/Documentation/devicetree/bindings/iio/resolver/ad2s90.txt new file mode 100644 index 000000000000..b42cc7752ffd --- /dev/null +++ b/Documentation/devicetree/bindings/iio/resolver/ad2s90.txt @@ -0,0 +1,26 @@ +Analog Devices AD2S90 Resolver-to-Digital Converter + +https://www.analog.com/en/products/ad2s90.html + +Required properties: + - compatible : should be "adi,ad2s90" + - reg : SPI chip select number for the device + - spi-max-frequency : set maximum clock frequency, must be 830000 + - spi-cpol and spi-cpha : must be defined to enable SPI mode 3 + +Note about max frequency: + Chip's max frequency, as specified in its datasheet, is 2Mhz. But a 600ns + delay is expected between the application of a logic LO to CS and the + application of SCLK, as also specified. And since the delay is not + implemented in the spi code, to satisfy it, SCLK's period should be at most + 2 * 600ns, so the max frequency should be 1 / (2 * 6e-7), which gives + roughly 830000Hz. + +Example: +resolver@0 { + compatible = "adi,ad2s90"; + reg = <0>; + spi-max-frequency = <830000>; + spi-cpol; + spi-cpha; +};