From patchwork Thu Dec 14 11:49:38 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mark Brown X-Patchwork-Id: 10111917 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 4AE7460327 for ; Thu, 14 Dec 2017 11:49:45 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 3976D28390 for ; Thu, 14 Dec 2017 11:49:45 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 2CF0129C28; Thu, 14 Dec 2017 11:49:45 +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=-6.8 required=2.0 tests=BAYES_00,DKIM_SIGNED, RCVD_IN_DNSWL_HI,T_DKIM_INVALID 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 DD56C28390 for ; Thu, 14 Dec 2017 11:49:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751880AbdLNLtn (ORCPT ); Thu, 14 Dec 2017 06:49:43 -0500 Received: from heliosphere.sirena.org.uk ([172.104.155.198]:60860 "EHLO heliosphere.sirena.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751198AbdLNLtm (ORCPT ); Thu, 14 Dec 2017 06:49:42 -0500 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=sirena.org.uk; s=20170815-heliosphere; h=Date:Message-Id:In-Reply-To: Subject:Cc:To:From:Sender:Reply-To:MIME-Version:Content-Type: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:References: List-Id:List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner: List-Archive; bh=blf0JQnY5/If3FqTM7UlvU0mTVZklgTLLuQwp7cVXuE=; b=A/tbIl8MyccY 7MQmUNszxn9TFOn+XxXy6URVlDSzPtLio+IEd03WrZHsxGMGDu4XtuDaagX1pgTUv2M+s8Jbh4DOo AIcoJrfbp/HjX5WE2ijmD4Ta8omlNd7u1LTWlVL/p1aS/g5i5KVXF6NpZwc9fSpJi3h9ppKgBCOSr w+qxk=; Received: from debutante.sirena.org.uk ([2001:470:1f1d:6b5::3] helo=debutante) by heliosphere.sirena.org.uk with esmtpsa (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1ePS1D-0004S2-Br; Thu, 14 Dec 2017 11:49:39 +0000 Received: from broonie by debutante with local (Exim 4.90_RC3) (envelope-from ) id 1ePS1C-0005U3-Tn; Thu, 14 Dec 2017 11:49:38 +0000 From: Mark Brown To: Geert Uytterhoeven Cc: Mark Brown , Mark Brown , Rob Herring , Mark Rutland , linux-spi@vger.kernel.org, devicetree@vger.kernel.org, linux-renesas-soc@vger.kernel.org, linux-spi@vger.kernel.org Subject: Applied "spi: sh-msiof: Document hardware limitations related to chip selects" to the spi tree In-Reply-To: <1513191913-10612-5-git-send-email-geert+renesas@glider.be> Message-Id: Date: Thu, 14 Dec 2017 11:49:38 +0000 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 The patch spi: sh-msiof: Document hardware limitations related to chip selects has been applied to the spi tree at https://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi.git All being well this means that it will be integrated into the linux-next tree (usually sometime in the next 24 hours) and sent to Linus during the next merge window (or sooner if it is a bug fix), however if problems are discovered then the patch may be dropped or reverted. You may get further e-mails resulting from automated or manual testing and review of the tree, please engage with people reporting problems and send followup patches addressing any issues that are reported if needed. If any updates are required or you are submitting further changes they should be sent as incremental updates against current git, existing patches will not be replaced. Please add any relevant lists and maintainers to the CCs when replying to this mail. Thanks, Mark From c99182f73cce7926c623b5c1c0ff0b7954ac8d81 Mon Sep 17 00:00:00 2001 From: Geert Uytterhoeven Date: Wed, 13 Dec 2017 20:05:13 +0100 Subject: [PATCH] spi: sh-msiof: Document hardware limitations related to chip selects Guide users to maintain the proper balance between native and GPIO chip selects. Signed-off-by: Geert Uytterhoeven Signed-off-by: Mark Brown --- Documentation/devicetree/bindings/spi/sh-msiof.txt | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/Documentation/devicetree/bindings/spi/sh-msiof.txt b/Documentation/devicetree/bindings/spi/sh-msiof.txt index bc8c16a6cfc8..80710f0f0448 100644 --- a/Documentation/devicetree/bindings/spi/sh-msiof.txt +++ b/Documentation/devicetree/bindings/spi/sh-msiof.txt @@ -41,6 +41,16 @@ Optional properties: 0: MSIOF_SYNC 1: MSIOF_SS1 2: MSIOF_SS2 + Hardware limitations related to chip selects: + - Native chip selects are always deasserted in + between transfers that are part of the same + message. Use cs-gpios to work around this. + - All slaves using native chip selects must use the + same spi-cs-high configuration. Use cs-gpios to + work around this. + - When using GPIO chip selects, at least one native + chip select must be left unused, as it will be + driven anyway. - dmas : Must contain a list of two references to DMA specifiers, one for transmission, and one for reception.