From patchwork Fri Jan 25 12:24:23 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jonas Bonn X-Patchwork-Id: 10781325 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 A733013B5 for ; Fri, 25 Jan 2019 12:24:47 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 936FC2EE23 for ; Fri, 25 Jan 2019 12:24:47 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 881082EE5E; Fri, 25 Jan 2019 12:24:47 +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 773FA2EE23 for ; Fri, 25 Jan 2019 12:24:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726289AbfAYMYa (ORCPT ); Fri, 25 Jan 2019 07:24:30 -0500 Received: from mail-lj1-f195.google.com ([209.85.208.195]:38941 "EHLO mail-lj1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726100AbfAYMYa (ORCPT ); Fri, 25 Jan 2019 07:24:30 -0500 Received: by mail-lj1-f195.google.com with SMTP id t9-v6so8204235ljh.6 for ; Fri, 25 Jan 2019 04:24:29 -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=Ap3WJXi6N0MaUhuDdAWlD/0LwseVhRF0+wzqnXt9JsE=; b=N1hlQ2v3e4qJwOnJHt23ThoGYV8GnbwHxZVK4gq79hzmgA3FdvRV1qUg6kP7IXIj/H yWYTy8gdP7KKCzStohbrRWeXyccgm4JGDx6umLx8B+gRYM4Cz78qYyrDkxs+SRxs7ZXZ OPT36udNGMVHIRD4YCxhVVYWIYkBN00dpNo3jVP9d/g8cy0mi9e3lzT6KjvXpGznJaxM 7/KjQTqlnrTrZa6cx3odHOeBOVeEIxYvVxISx6jGNhnieBcEfFLZ02jIpuLalHxy7SkQ PYzyZLI32Br0ZiBQwSFppKEzasPagMd9gNbDiAoEDChueGQZaxpoBxRa084lksWHOOZ0 E5Hw== 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=Ap3WJXi6N0MaUhuDdAWlD/0LwseVhRF0+wzqnXt9JsE=; b=Ug9rG+VPoyKdm2dhqNYbVtqyRbUBQfUpt+kBcX0kA1VVg88MCxhhgxvst0G2gjskP7 zvzMluwjQ1NdtWsP3IVrLbm2V3eCXIUWFGjY08zPotAcWCZ7tmsFHUiASGncaKlzjJsp gnfq36tG9jMa4lS68LWiti6qLxW92V63W0YWibJZ9WwQFqfU1XWsfDw+Kj1jROlRQhbn URw/TNM953Md6dHhlCi57F3hjYxHn45zuvmwD+5qQ8i9wQ4cGeYqAYjkiQAkv13+rUwd wzdyqHf/3KjQmGPYjb9QAxI9/YLapwqhq0bVKar+OwgJxsYzhUXNOFRQm4NCvpezK9Pw beww== X-Gm-Message-State: AJcUukd6AVXuGZUA9/VAzlZ57RnzNLVLCNJgPO+ea7F4KtefnhObzaC9 rb4i2mmMGfAPH8IwOfdHNIKEKcWbaUY= X-Google-Smtp-Source: ALg8bN5rESJROxSMX8inCJCYWAaFNqMf/7krSjLH9H5SEiINriqiT9Xt2kqKPJLAFbNLzLGBbrexwA== X-Received: by 2002:a2e:8945:: with SMTP id b5-v6mr9597207ljk.55.1548419068337; Fri, 25 Jan 2019 04:24:28 -0800 (PST) Received: from mimer.lan (h-29-16.A159.priv.bahnhof.se. [79.136.29.16]) by smtp.gmail.com with ESMTPSA id y81-v6sm1508376lje.30.2019.01.25.04.24.27 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 25 Jan 2019 04:24:27 -0800 (PST) From: Jonas Bonn To: linux-kernel@vger.kernel.org, linux-spi@vger.kernel.org Cc: Jonas Bonn Subject: [PATCH v2 0/2] spi: support inter-word delays Date: Fri, 25 Jan 2019 13:24:23 +0100 Message-Id: <20190125122425.30676-1-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 Resubmission to fix thinko in spi-atmel patch. Changed in v2: * Fix atmel-spi driver to not unconditionally set minimal delay if no delay is required (erroneous clamping) 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 .../devicetree/bindings/spi/spi-bus.txt | 1 + drivers/spi/spi-atmel.c | 18 +++++++++++++----- drivers/spi/spi.c | 4 ++++ include/linux/spi/spi.h | 1 + 4 files changed, 19 insertions(+), 5 deletions(-)