From patchwork Fri Jan 25 11:44:27 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jonas Bonn X-Patchwork-Id: 10781243 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 81D0D139A for ; Fri, 25 Jan 2019 11:44:50 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 6F2322EEE2 for ; Fri, 25 Jan 2019 11:44:50 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 630302EF09; Fri, 25 Jan 2019 11:44:50 +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 0913D2EEE2 for ; Fri, 25 Jan 2019 11:44:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726804AbfAYLoe (ORCPT ); Fri, 25 Jan 2019 06:44:34 -0500 Received: from mail-lf1-f68.google.com ([209.85.167.68]:36483 "EHLO mail-lf1-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726049AbfAYLoe (ORCPT ); Fri, 25 Jan 2019 06:44:34 -0500 Received: by mail-lf1-f68.google.com with SMTP id a16so6716887lfg.3 for ; Fri, 25 Jan 2019 03:44:33 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=norrbonn-se.20150623.gappssmtp.com; s=20150623; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=1uZgeytfHcFfoxxwaJPRe+nMKCIYtTyciuS0VyMLAl0=; b=hgRyAVQR/JxBzSyWetarj8knMgSFD/WDjVWg2isDKSBIcHphNqDQ6YKu0fQrTStlMB OJs07Os9s+jYwPXfnunj0E6FcqaR8dF9uV/80UzoXBwx96kR28irhLy6ya3hrVoLdpNd vQP/7LPfKv5xGe8crcqx7Lvok3M3alOkkcVsDgPdQqXjGr5cAQdWt6a5BzIF4fO6Ue2E huIAq4YljM0u4Nbo1MQL+pthruIv8YKTrmY5MLHPAvOk43vM8z03RX3iyvGyrobUadz9 Y7zxY+zH9yWQeBraXCCv9Lh3t/4DrBxsF/v/nrmrUsE908AHfEojZjvJqPf10laOE6Sp bQOQ== 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:mime-version :content-transfer-encoding; bh=1uZgeytfHcFfoxxwaJPRe+nMKCIYtTyciuS0VyMLAl0=; b=qSuJwrQVdqU4s5e3Uv+IMfhcCDolUeTV7gwcrYb3hxfeKg7056BPDYMqfo+hMSt/hT VOEhUmpH4cglNlwThiDCQt4jMJha05bnK86QLEQyJRmp9kErCq7lFUZX36yke5xOOCjw yVrV3lX4RsJ2tpR1zKs/DiN64C37Nh8Vh9Vc8jhciF/gjT0vlgwqZC0Srieo1XsKvPUz 2JLoxDzHVS1FS1u3PZgkMjeFdaMxwEpZ372sRZZIdLmNgCx/rRYFbKsY/M+ctt+kbBrG jcf8FKpPxhMO7+RANjKO9DdyOcKklRD+xR4Wkf3LM+pr3o8FfHIYj8q++5usFXjZmlDF nVXA== X-Gm-Message-State: AJcUukfOHQwzKnngq4VpeJSoj38J67EsfreYMx4jwW8qG9/uE9N/2W2A 3T2SoHKxy+e2G2p7lJelO59sDA== X-Google-Smtp-Source: ALg8bN7V9lQNIdgdU/gKYAG2vuhxH/ygZj73KJNHy/qQ8qoTx/5/KuI/oqFD2D3HUAbQwymgN22O/g== X-Received: by 2002:a19:7352:: with SMTP id o79mr8668259lfc.104.1548416672309; Fri, 25 Jan 2019 03:44:32 -0800 (PST) Received: from mimer.lan (h-29-16.A159.priv.bahnhof.se. [79.136.29.16]) by smtp.gmail.com with ESMTPSA id l3-v6sm1490962ljg.21.2019.01.25.03.44.31 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 25 Jan 2019 03:44:31 -0800 (PST) From: Jonas Bonn To: linux-kernel@vger.kernel.org, linux-spi@vger.kernel.org Cc: Jonas Bonn Subject: [PATCH 0/2] spi: support inter-word delays Date: Fri, 25 Jan 2019 12:44:27 +0100 Message-Id: <20190125114429.20066-1-jonas@norrbonn.se> X-Mailer: git-send-email 2.19.1 MIME-Version: 1.0 Sender: linux-spi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-spi@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP This short series adds support for SPI inter-word delays and configures the spi-atmel driver to honour the setting. Some SPI slaves are so slow that they are unable to keep up even at the SPI controller's lowest available clock frequency. I have such a configuration where an AVR-based SPI slave is unable to feed the SPI bus fast enough even the SPI master runs at the lowest possible clock speed. Jonas Bonn (2): spi: support inter-word delay requirement for devices spi-atmel: support inter-word delay Documentation/devicetree/bindings/spi/spi-bus.txt | 1 + drivers/spi/spi-atmel.c | 11 ++++++----- drivers/spi/spi.c | 4 ++++ include/linux/spi/spi.h | 1 + 4 files changed, 12 insertions(+), 5 deletions(-)