From patchwork Wed Dec 9 17:57:07 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Aswath Govindraju X-Patchwork-Id: 340451 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.5 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id D7749C4361B for ; Wed, 9 Dec 2020 17:58:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7D2E823C8F for ; Wed, 9 Dec 2020 17:58:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726576AbgLIR6R (ORCPT ); Wed, 9 Dec 2020 12:58:17 -0500 Received: from fllv0016.ext.ti.com ([198.47.19.142]:56352 "EHLO fllv0016.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725972AbgLIR6R (ORCPT ); Wed, 9 Dec 2020 12:58:17 -0500 Received: from fllv0034.itg.ti.com ([10.64.40.246]) by fllv0016.ext.ti.com (8.15.2/8.15.2) with ESMTP id 0B9HvK6F043926; Wed, 9 Dec 2020 11:57:20 -0600 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ti.com; s=ti-com-17Q1; t=1607536640; bh=n2EdWdd2h0GvAOC4E08Jb6Cv4a45zDdLDR18BXOJQv4=; h=From:To:CC:Subject:Date:In-Reply-To:References; b=gmbqirQKH4aCt0ZakLGl5Nqhn5vhNouSmwOiRoBMB+ccR7uyg8vPfq+DR5406MqsN S/vJB767kQD113Fjq5l0f4sOZHDU7lvrEhQ3fWSL29kFXQHeHv4S69VfV/Mcd3D1Eo tFFYQRwA6VIvY7liEzJzOZTgY0mWGxGzNe5Y4MEQ= Received: from DLEE113.ent.ti.com (dlee113.ent.ti.com [157.170.170.24]) by fllv0034.itg.ti.com (8.15.2/8.15.2) with ESMTPS id 0B9HvKaJ047440 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=FAIL); Wed, 9 Dec 2020 11:57:20 -0600 Received: from DLEE112.ent.ti.com (157.170.170.23) by DLEE113.ent.ti.com (157.170.170.24) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.1979.3; Wed, 9 Dec 2020 11:57:19 -0600 Received: from fllv0039.itg.ti.com (10.64.41.19) by DLEE112.ent.ti.com (157.170.170.23) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.1979.3 via Frontend Transport; Wed, 9 Dec 2020 11:57:19 -0600 Received: from gsaswath-HP-ProBook-640-G5.dal.design.ti.com (ileax41-snat.itg.ti.com [10.172.224.153]) by fllv0039.itg.ti.com (8.15.2/8.15.2) with ESMTP id 0B9HvATG094634; Wed, 9 Dec 2020 11:57:16 -0600 From: Aswath Govindraju CC: Rob Herring , , , Arnd Bergmann , Greg Kroah-Hartman , Vadym Kochan , Vignesh Raghavendra , Sekhar Nori , Aswath Govindraju Subject: [PATCH RFC 1/2] Documentation: devicetree: Add property for ignoring the dummy bits sent before read transfer Date: Wed, 9 Dec 2020 23:27:07 +0530 Message-ID: <20201209175708.16252-2-a-govindraju@ti.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20201209175708.16252-1-a-govindraju@ti.com> References: <20201209175708.16252-1-a-govindraju@ti.com> MIME-Version: 1.0 X-EXCLAIMER-MD-CONFIG: e1e8a2fd-e40a-4ac6-ac9b-f7e9cc9ee180 To: unlisted-recipients:; (no To-header on input) Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org Dummy zero bits are sent before data during a read transfer. This causes the data read to be shifted to the right. To fix this send zero bits after the address during a read transfer. Add property to send zero bits after the address during a read transfer. Suggested-by: Vignesh Raghavendra Signed-off-by: Aswath Govindraju --- Documentation/devicetree/bindings/misc/eeprom-93xx46.txt | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/Documentation/devicetree/bindings/misc/eeprom-93xx46.txt b/Documentation/devicetree/bindings/misc/eeprom-93xx46.txt index a8ebb4621f79..09fb1cec54f0 100644 --- a/Documentation/devicetree/bindings/misc/eeprom-93xx46.txt +++ b/Documentation/devicetree/bindings/misc/eeprom-93xx46.txt @@ -10,7 +10,9 @@ Optional properties: - read-only : parameter-less property which disables writes to the EEPROM - select-gpios : if present, specifies the GPIO that will be asserted prior to each access to the EEPROM (e.g. for SPI bus multiplexing) - +- read-op-dummy-cycles: If present specifies the number of dummy zero-bits to + be sent after the address during a read transfer to ignore any bits sent + preceding the data. Property rules described in Documentation/devicetree/bindings/spi/spi-bus.txt apply. In particular, "reg" and "spi-max-frequency" properties must be given.